Jump to content

Recommended Posts

I spoke too soon and jinxed it...  We had a bad thunderstorm the other day and the wife noticed the windows were fogging up.  I went out there and sure enough the roof was leaking, again.  It was in a new spot now though at least.  I am going to do a temporary Flex Seal fix on it, if I can find the ingress spot.  That did an awesome job in the other trouble area.  Since I already have those supplies.  


The whole roof will be properly resealed with some sort of complete seal solution here shortly.  I have a couple more pressing problems to tackle first.  The ladder is pulling out in the middle.  And it feels like it is attached to paper.  It is right before the transition and I can see that line inside behind the kitchen drawers.  I think I have to pull the stove out to get to the area though.  I am thinking that bonding some 3/4 high grade ply across as large of an area as I can get it to cover, should give me enough stability for the ladder mount.  


For now, I am sure to my neighbors dismay, I just tarped the roof again.  Another problem I need to give some thought to, is a walkway/crawlway.  I suspect that a recent trip up on the roof to install a Reolink camera and solar panel, put the stress on it causing the new leak.  I want to put some sort of simple planking down across the support beams to help prevent this.  I need to grab pictures of those beams, I don't think they are original.


I discovered another leak.  The black or grey water tank (not sure which but I think it is the grey one) has a small crack.  It is small enough, I should be able to safely patch it with some marine tank epoxy.  I need to figure out how to power up the water pump, and fill all the tanks.  Might as well check them all 100% before proceeding with that repair.  


I also need to finally grab some leveling blocks, or park it on the street for a few hours, and check operation of the refrigerator.  It is an expensive enough item to replace, that it will put a serious damper on finishing it.  Especially the wife's 'financial willingness" to do so.  Yet seeing one more system online, will help with that motivation!      


I got new headlights.  One was out and turns out that in my big box of sealed beams, I didn't have a single correct H6054 unit.  I grabbed some Autopal H4 conversions with city lights.  Although that part was a bonus.  They were out of stock on the regular ones and asked if I wanted a free upgrade to the ones with city lights.  Heck yeah!!!  I would have gotten those instead if I had seen them anyways!  


I haven't decided how far I will take the headlight upgrades.  I will likely just put some stupid bright halogen rally bulbs in and relay it.  I really want to build some projectors and I have a box full of HID setups too.  But I grabbed standard lenses not realizing Autopal had crystal ones avalible.  The effort for the H4 upgrades though is so minimal and I have done that on plenty of prior car builds.  The yellow halogen light is gentler on my older eyes too.  And even with my old setup running 120/180 watt rally bulbs, I didn't get flashed on low.   If I feel extra lazy, for $20-30 I can even buy the relay upgrade setup premade.  My old setup though I made myself with 4 relays and individual fuses.  I have the parts on hand to make another too.  A lot of work though so we shall see, lazy might win here.  


I am still torn on the taillights.  I can get some cheaper surface mount LED ones for as little as $30.  Or I can get the Bargman ones for $120, but they have to be recess mounted.  As much trouble as the Bargman ones are, I am leaning that way a lot more.  But at some point you have to make decisions on continuing to pour money into a project this far from completion.


What do you guys think, should I spend the extra on the Bargmans?  Tough call.  The Bargmans are slightly more of a project, but do it once?  The others I would be replacing the whole deal if one goes bad.  I just really can't convince myself the cheap $30 ones will be worth the savings.  


I am taking on one unnecessary expense/project now though.  I probably shouldn't, but I am going to MegaSquirt the Toyota 22RE.  For any that might not know, this is a DIY engine management system.  For me, it won't cost much.  I already have everything needed hand except for a handful of small parts.  Injectors, maybe an adjustable fuel pressure regulator, and maybe GM coolant and air sensors.  (Maybe because I might actually have some GM ones on hand, and I could use the Toyota ones if I really wanted to.  The GM ones are super accurate and cheap though.)  Out the gate the only expense I know I will be outlying for will be the injectors.  


Why?  Mostly, because I can.  I have been a part of the MegaSquirt community almost from the very beginning 20yrs ago.  I have a REALLY nice MS3 system sitting here collecting dust with all the bells and whistles.  I think it was close to $1400 when added up.  Boredom plays a part I am sure, I really miss doing this and enjoy tuning.  Tuning an RV, should be extra amusing.  


Performance and Fuel Economy are my main excuses.  I don't know what the stock MPG for these are (somebody in the know please speak up!) but from experience I am certain I can add at least 5 mpg to that number.  I have made some serious MPG gains on all of my prior conversions from vintage fuel management systems.  Horsepower gains will be there too.  While the overall number might not be as drastic, the power under the curve will be a whole new beast.  I can tailor the timing and fueling exactly where it is needed.  


Performance:  Again, probably no drastic number changes here.  But the motor will be a lot snappier and the intake much less restrictive with the flapper fuel meter removed.  Once I collect the funds and parts, a turbo will eventually go on, that will make a massive difference.  


Economy:  The first part of this is also prep for later turbo conversion.  Larger and MODERN fuel injectors.  Modern fuel injectors have a much better spray pattern.  I can improve this even more with a slight fuel pressure increase using an adjustable fuel regulator.  As odd as it sounds, this alone can easily get a couple more MPG over stock.  Next, a wideband will allow me to lean out the engine at cruise while still maintaining the safety.  Throttle tip in on a heavy beast like this is going to be where troubles would occur in the stock system.  And let's be fair here, there is LITTLE chance the stock ecu was mapped differently for the weight of the RV platform, compared to that of the normal pickup.  Yes, it compensates to some degree automatically since the engine determines the load via the flapper.  But with the engine tuned specifically for these conditions from the start, it will also be a lot more MPG friendly.


Here is where I could go MUCH further, but would have to start spending money to do so.  Upgrading the ignition system.  Some of what I would do here would not only give me a performance gain for the ignition, but also allow me to run sequential fuel injection, and gain even more MPG.  I have only tuned/modified a couple 22RE motors in the past though.  This would require some research and work.  While I might be able to utilize the signals out of the stock distributer to do this, part of the point would be to eliminate the distributor based ignition and go with a coil pack or even COP.     


Comfort:  A slight consideration.  In the future, I want to get the chassis/cab ac working again.  No idea why the old AC compressor was removed, but time alone could have killed it.  And I am sure it wasn't friendly to the fuel economy.  I can get around that with a little extra power, a better AC compressor, and ECU control of the compressor.    


Diagnosing and maintenance.  Sure the stock system is dirt simple and fairly easy to diagnose issues.  I am adding complexity, and potential issues with the conversion.  But especially once a turbo is added, my familiarity with MS will outweigh that and make any engine related issues much easier to hunt down.  I chased my tail in the very beginning and almost put a MegaSquirt in thinking I had a bad Toyota ECU and/or wiring issue.


Security and peace of mind:  While the engine wiring seems okay, it is 36yrs old!  I already have to chase down (or ignore) the odd no crank with key issue.  Lights are all being upgraded to eliminate the issues old age had caused.  While necessary, they won't strand me on the side of the road.  Sure, the engine wiring probably won't either, but why give it that chance if I can easily solve it?!


No, this isn't a project I would recommend for most to bother with.  But as easy as things like solar upgrades, "house" wiring and plumbing, and other RV type upgrades are to you guys, I probably find rewiring an engine and putting it on standalone to be just as easy for me.


Roof and ceiling repairs, I find to be a lot more daunting...  If anyone wants to come do the house/roof repairs in exchange for me 'squirting their RV, hit me up!!!  I am sure we can make that happen!!!   


Lastly though, doing this will get me truly motivated to tackle the other less exciting and more daunting projects on it.  This is something I really enjoy doing.  It will add some value to it, at least enough to keep the wife from selling it out from under me LOL!  And it will give me, and probably her, a lot more peace of mind with it out on the road.  


It is happening sooner than later.  Yeah, ideally I should wait and get a before and after comparison especially on the driving feel and MPG.  But it is already down for the count.  Once it is ready to go and we finally take it out camping, I won't be parking and disabling it by choice.


Anyways for now writing this out has clarified and solidified my decision to move ahead with this particular project.  I need to do a little study and familiarize myself with the 22RE motor and its requirements.  It probably will take less time to do that, than I spent on writing this.  LOL!  By payday, I should have a clear idea what parts I need to order.  Need to do a little digging to determine what injectors will fit.  I think that might have been a problem on a past conversion.  Other than waiting for odd parts like that and solving the inevitable odd problem, the actual conversion shouldn't take me more than a few relaxed evenings to wire and get ready to go.  The ECU will take a couple evenings to mod and prep.  Even with some issues cropping up, I think I can have it online in 2 weeks.  Hopefully, the only real hurdle or roadblock will be getting the parts in time.  


Humm....  I bet the throttle body doesn't have a variable TPS sensor on it.  Ugh.  Actually cool, it seems to have that with a quick look under the hood!  Those injectors will suck to replace though lol.  A quick look around, and it has some interesting features, including an apparently variable fast air idle valve.  This is a pretty sophisticated engine management for 1985.  Still, I am SURE I can improve on it!  


Alright, time to dig in and do some proper research.  Hunt down some connectors, and draw out a harness routing plan.  










Link to comment
Share on other sites

  • 2 weeks later...
On 4/29/2021 at 9:46 PM, WME said:

Think lite, weight kills MPG and makes hills so LOOONG


On 4/30/2021 at 1:53 AM, thewanderlustking said:

Googling it, I am seeing an average of 14-16 mpg, but so far haven't found much mention of the the Mini Cruiser.  This is for the Dolphin.  Close, probably close enough?  I am seeing a handful of 20mpg estimates when lightly loaded.  The engine management in these is very outdated and horrible.  I have been through it and see a LOT of places where I can improve on it.  If I wasn't fighting aerodynamics and the weight of the house, I feel I could get this up to 30-36mpg.  That is pulling out ALL the stops including a computer controlled alternator.  Realistically, I feel I can hit 24-26mpg.  If I can get it at 20mpg loaded up, I will be happy.  Oddly, when I look for 22RE MPG, the numbers only go up slightly to about 15-18 on the pickups and 4 runners.  Doesn't seem like weight and drag hit as hard as I would expect them too.  


On 4/30/2021 at 1:27 PM, WME said:

20 mpg is unlikely, even with a MS efi mod. Its all HP, aero, weight  and gears. You have a way overloaded Toyota pickup. Speed really kills MPG most travel at 55-60 mph . Example in a perfectly tuned rv, 55 would give you 15mpg, at 60 you get 13 and at 70 you get 10.


I wanted to grab these posts from another thread where the discussion came up about MPG. 


Related tangent:  In fact today was interesting.  A nice young lady and her pretty awesome dog, found themselves with a Check engine light, a poorly running Ford 1996 Walkabout Class A, and at our shop Friday.  My boss had looked at it and was confident it was a bad injector.  He asked me to take a look and verify it this morning.  He was right, and we got it fixed for her.  Oh course she told me her trials and tribulations with the beast and how much she had put into it (The RV, not the dog LOL).  She was blown out of the water that one of our Toyotas could potentially get 14-16.  On a good day, she gets 8!


When I drove it, I was taken back by just how heavy it felt.  And how even with a 7.5L, my much smaller 2.4L actually felt peppier!  


Since it was a drivability problem, I also noticed just how archaic the engine management in it also is, with some striking similarities to ours.  And after spending 4hrs fixing it, I really appreciate just how much easier our Yotas are to work on!  I will go in order of attack from what I feel will make the most impact, to the least.


0)  Tire inflation.  Free, but super important.  I need to figure out what my ideal pressures are, but whatever.  This one "mod" easily can pay for any tire monitoring system, in money back in fuel savings, and saved tires.  


1)   The Engine Management ECU.  Nothing that follows can be done without changing this out first, to something programable.  


2)  Advanced Air Fuel feedback, specifically a wideband Oxygen sensor.  While many hundreds of hours on a dyno can somewhat make up for having an outdated narrowband oxygen sensor on a normal vehicle, there is a pretty predictable weight range for most vehicles.  Not so much for an RV.  A wideband oxygen sensor can not only make up for this, but it can also far exceed a narrowband allowing safe lean operation where it is reasonable/safe for that to be.  More than a few times I have taken a car tuned specifically just for performance, and gotten 5-10mpg back without the customer noticing a difference, by addressing the areas.  An older engine management system doesn't have the resolution in their maps to do this, or the brains and tenability to safety allow for it.


3)  Not sure where this one falls, but no car I can think of after 1990 and OBD1, have a flapper fuel meter in the engine bay.  These are HORRIBLY restrictive, power robbers, and not very accurate.  For a system to meter fuel well. it needs this to be more accurate.  I started tuning fuel injection by modifying these back in the '90's lol...  In fact figuring out how to get my highly modified Fiat 2000 with Bosch L-Jetronic to actually run right, started me down the path to where I am now.  I literally had every manual on fuel injection I could find.     


4)  Fuel injector design.  Older fuel injectors suck.  They do not have anywhere near as good of atomization.  There is a HUGH difference in injectors from the 80's and 90's, to ones from the '00s to now.  In fact simply putting more modern injectors in older cars will actually show some small (2-3mpg) improvements.  But a couple more changes need to be made for real improvement.  Bumping the fuel pressure up, and adjusting the injector parameters also helps tremendously.  This next part is an assumption based on what I have seen and experienced, but not backed up by facts/research.  Older cars, like our Toyotas, also ran low impedance injectors.  I have yet to see  single modern car run low-z injectors.  Precise control with high-z seems to be much better.  While out factory ECU's effectively think they are running high-z injectors, they do this by adding resistor packs in.  Something is still lost in translation though.


5)  Ignition system.  No modern cars come with distributers, cap, rotor, and wires, why?  Fuel economy.  EPA wants cars to reach a certain level.  They don't do this without more precise control.  And they loose spark energy to ignite the better fuel mixtures modern injectors have.  


Tangent:  A friend of mine fried the ignition module in his 1983 Jeep.  It was that weird Ford module that is made of unobtanium.  I think he was able to find some used ones, but even they were going for outlandish prices.  I had a MegaSquirt and thought, well why don't we use that as an ignition module instead?!  He had a nice Holley 4 barrel setup and didn't want to spend the money or time to upgrade that also.  So we just "MegsSparked" it!  It has been years and I don't remember the exact numbers now, but there was an unexpected side effect.  Even with a Holley 4 barrel, his fuel economy suddenly shot WAY WAY up after we squirted sparked it.  And it drove like a COMPLETELY different beast.  


Now to really see a huge difference on the 22RE motors, I have limitations here on the stock ignition system.  Our "crank signal" is driven off of the distributer at 2x speed.  Some loss of precision occurs in the timing chain.  And then some in the distributer setup itself.  Some have 24 teeth, some only 4.  They have a second reluctor wheel with 1 reset that can be used for a cam signal.  This isn't an ideal, or very precise setup.  At the moment I haven't opened up mine to figure out what is inside it.  These limitations very well might prevent me from running Coil on Plug without changing to a crank wheel sensor.  And even that alone doesn't allow me to run proper COP in single strike mode, without a cam reset.  For now, while I still need to know, the truck gets setup without the crazy COP ignition upgrade anyways.  


6)  Performance, this is an interesting one.  So as we all know, increased displacement is an easy way to increase performance, and also fuel consumption.  But what many don't realize, is that turbocharging is an artificial way to increase effective displacement and also performance, but without the same fuel cost of increased displacement.  Big diesel rigs are almost all turbocharged because the increased engine load translates to increased exhaust pressure, spinning the turbo harder, and scavenging otherwise lost power in the process.  Yes, it does take more fuel to fuel the turbo, but at a MUCH of a fuel economy cost than simply increasing the displacement.  


7-10)  Random number picked...  There are a whole lot of other tricks that can be employed to also improve power, and fuel economy.  Running flex fuel, water injection, knock detection etc etc.  Most of these are in relatively easy reach for me to utilize, but start to require tuning and setup that more than likely will bore me long before I get to that point.  Water injection is fun, and I do have an awesome vintage Aquamist/ERL system from back in the early days of my tuning adventures...  So who knows.  


11)  I won't likely bother with this one, even if I end up with the right engine setup to run it.  Sequential Fuel Injection.  This is something that modern manufactures will always beat out a "tuner" on.  Dyno time.  For this to really be effective, each engine type and installation needs hundreds to thousands of hours of development time.  Individual cylinder and exhaust temp monitoring.  And lots of expertise and specialized equipment.  I have played with this in the past and usually end up with an engine that doesn't run as smoothly.  


12)  At some point, we are stopped by the inefficiencies of our older engine design.  While most of this is in the fuel, spark, and intake, at some point the motors themselves reach the limit of what they are capable of performance and economy wise.  Performance on the 22RE, we have a lot of room for improvement there.  Economy?  I am not so sure about.  To a point, a turbo can compensate for a lot of intake inneficiancies.  But they can add some too.  


There is only one item I am likely to change inside the engine that will put enough economy back into the equation to be worth considering.  A camshaft designed with no or minimal overlap for boost.


WME brings up a REALLY GOOD POINT though!


WEIGHT WEIGHT WEIGHT is the KILLER!  So I am going to approach everything I add to the beast with extra thought and care.  I have noticed how weight frugal the interior assembly is.  The framing on the kitchen seats, most of it is 1/8 luan and not big heavy panels.  The cabinets, not thick panels, but hollow structures.


Honestly, I thought this was just cheap manufacturing until really starting to delve deeply into this vehicle.  The RBR MiniCruiser Yotas seem to heave one of the best reputations for quality out of all the Yota micro RVs.


With all that said, very little of this would pay back the crazy investment in time and money it would take for most to pull it off.  I just so happen to have boxes of random goodies from many years of tackling silly projects like this.  A friend also approached me a couple months back and said, "I want to try and double my fuel economy on my XXXX brand car. Lets turbo charge it!"  I laughed, said he was a weirdo and a lunatic.  He said, "Sure, but the car is free so I don't care about the money, lets do it!"   The tuner shop told him he wouldn't see any fuel economy improvement without hours of dyno time, I called BS because I have actually done it as an amusing side note on plenty of past installs that I have done.


I SERIOUSLY doubt we can double up on his fuel economy, and I am fairly certain I can't double mine.  But who knows.  If I only have to get to 20mpg under those less than ideal circumstances, I might actually be able to do it.  Although I am reasonably certain that right now driving this thing at 70mph, would scare the CRAP out of me...     


Last thought, then I go away and read my assigned homework and promise not to post pages long ramblings for at least a few more days...  Without a decent HP increase (that doesn't greatly cost in fuel economy), this isn't worth doing other than as an exercise in amusement and boredom.  The MS EFI mod alone, near pointless.  If I leave the whole system as is, changing only that one part, it won't get me very far.


I will take the estimated 14-16mpg as a middle baseline unless you guys want to propose one you feel is more accurate.  I should drive this beast and get a before baseline, but I already have most of what I want on hand to start on the conversion, and I need a couple other items sorted before it is out on the road.  Now is a better time to take it down, then later will be.  After it is on the 'squirt though, I likely will be attacking those upgrades only 1-2 at a time.  Turbo won't come until later.  Those are the only parts I don't already have on hand.  


And since I wrote the last post above, the plans have changed ever so slightly...  I am going to keep quiet on that tidbit for now though.  I don't want to jump the gun and jinx anything...  But I do have a special part arriving Monday.  My next post (for this thread anyways) will be some sort of real progress!                  





Link to comment
Share on other sites

A great part of the problem is the vehicle it's self it has all the aero dynamics of a brick and a matching weight. The coefficient of drag increases with speed very quickly. My modern Tacoma can yield maybe 24 MPG on the highway if I keep the speed down. Connect my 17' trailer I'm down to at the most 14 at 55. Never did much better than 13-14 with the little motor home I have found that towing any thing with truck or a motor home for that matter has the same effect no matter what you tow or drive it with it's right in the 10-15 mpg. There are certain things you just can't fix.

Link to comment
Share on other sites

Posted (edited)

Certain things you can fix though.  Nobody here will claim their 113hp 22RE engine has enough power.  And the 22RTE turbocharged engine isn't much better at 135hp.  What any competent tuner will ask, is how on earth they turbocharged an engine and only gained 22hp?!  

Now think about this.  Your modern Tacoma is possibly close to double the weight.  So lets say you go in with a sawzall and cut out half that weight.  What will happen?  Your fuel economy WILL GO UP.  (The truck would collapse too, but ignore that).  A funny thing happens though when you put a more powerful engine into a lighter vehicle, fuel economy goes up.  


Whats the worst that will happen?  Well there is ZERO chance that I will loose power and or fuel economy by improving the engine management.  Sure, if deliberately tried really hard to do a bad job tuning it, I could probably manage that. But I have more than enough seat time to know that won't be a concern.  


Also if you read through what I wrote above, you will realize, I have probably done this a few times before...  🙃  Things WILL improve.  How much improvement and where?  Well that's the fun part!  At this point I can only make some educated guesses of possible outcomes.  I haven't plugged numbers into any desktop dyno software, nor am I likely to bother as it wouldn't be easy to come up with enough accurate ones to plug in.  



Edited by thewanderlustking
Link to comment
Share on other sites

Well like I said it is not brand dependent my 4 liter V6 Tacoma has more than enough power but towing I get the same results as I did with my 87 22RE it pulled it OK but the gas milage sucked. I have noticed the same results with my dually Dodge Diesel it pull a load fine don't even have to shift much with a millage hit also. Yeah more power is better less towing or driving in the right lane and trying to get a running start to an incline but it's not going to do much for mileage. To get max power with a turbo it has to have more fueling so if the stock injectors are used you are going to end up with a lean mix and and maybe burnt pistons if it carburaburated larger jets will be needed. It takes fuel to make power so yeah it makes for a bit more pleasant drive perhaps but you will see very little difference in mileage and it may even be worse. 

Link to comment
Share on other sites

I believe somewhere in this forum someone was able to fit a lexus 6cyl motor into their camper. I believe the person was suggesting significant bump up in performance and gas mileage. All different ideas and investments in time and money on this site. Some of us just settle into a finely tuned 22re with 12-15mpg. 

Link to comment
Share on other sites

There have been a couple conversions done. The engine is a Lexus V-8 (1UZ-FE). Ive scraped a couple of the engines.  Talk about a befuddlement, they are so well built and long lived  that they have no value in a salvage situation. No body buys a salvaged one to replace their worn out engine.

The big problem is cooling, the engine fills up the engine bay and blocks a lot of air flow through the radiator.

Replacing the Toyota 3L V-6 with the Toyota 3.4L V-6 has been more successful.

Link to comment
Share on other sites

Posted (edited)

Maineah, stop and take some time to read through what I posted above.  Really read it.  None of your points are relevant to what I wrote there.  Obviously, I am talking about a more advanced solution that a carburetor.  I also specifically state, our injectors SUCK.  I went into extreme and probably painful details about just why and how I would fix that. So I probably have a better idea than average as I promise you I didn't have to spend three days, or even 3 minutes researching what I wrote just then.  The effort was all in putting it down here.        


If what you're saying were true, then our motorhomes would only get 8mpg like almost everyone else's do...  Of course that statement alone could be used to argue you're right.  We could ignore the one outlier...  But everyone here already knows our Toyotas are that exception to your theory.  It is very true that drag and weight of our vehicles is a MUCH bigger obstacle to overcome than it would be on a pickup or Corolla.  But it also isn't a "dead stop" issue.  


Maineah, if you want, I will happily explain some of the nuances even further.  But don't worry, I am not going to add a turbo and expect the stock injectors to accomplish anything.    


Scott, I stumbled across some references to that.  I would LOVE to find more info though.  But that is also EXACTLY the outcome and point of what I am doing and saying here.  I just believe I can take the 22re sitting in my engine bay, and take it MUCH further past just a good "tune up."


Honestly, I would love to also know what your own definition of finely tuned is?  I would LOVE to hear what you, or anyone else here, has done to squeeze everything out of our little 4 banger 22re engines!  Post up PLEASE!!!    


I am actually hoping to offer a solution back to you guys, that takes a lot of the difficulties out of what I am trying to attempt.  For me, this stuff is easy.  I can tune engine management half asleep.  I have even done an install with my buddies making a point to keep me three sheets the whole time, and it ran good too!   I don't know what this final solution will look like yet though... 


There already is an "almost" plug and play MegaSquirt ECU available for our trucks.  4Runner/Pickup 22RE/22RTE MSPNP Gen2 Plug and Play ECU  I have some issues with it though.  The cost is fairly reasonable for what it is.  But it isn't a complete solution either.  First issue is VERY minor and nitpicking, it doesn't actually bolt in.  Gotta drill some holes.  Pretty sure most here can do this.  If not, well maybe this is a bad idea already LOL!  Still that case isn't going to be seen, and isn't as well sealed up as the stock cases are.


Next issue, it requires a wideband oxygen sensor setup.  Yes, ANY install will require this.  But this is a price thing as the ecu is already $799, and a wideband sensor is about $200.  Different options are available from much cheaper to much more expensive, but they all require another installation.  While the stock sensor "could" be used, for what we are doing this for that wouldn't be smart without well tuned maps.  Even then, still smarter to have.  I mean you can drive cross country without a tire monitoring system, but it has been years since I have seen a SINGLE rv without one...  


The maps that are out there are for a different purpose.  Little AE86's and Corollas, maybe a pickup or two, making as much power as possible.  So even if somebody bought the above ECU, they would need to have a good idea what they were doing to retune it to our unusual use case, an RV.  


This is where I have a BIG DISCONNECT with the price for the DIYAutotune PNP.  It is already outdated.  It is running an MS2 processor that development has stopped on.  It is missing a lot of features that MS3 has.  It has an outdated serial port connection, requiring another small investment in an adapter, or a large investment in a capable laptop.  If it were much cheaper, small issues.  But it isn't.  $399 or even $499?  Maybe, but still need the other bits and it isn't a complete solution.


Now if the WHOLE package to install ECU AND the supporting bits fell in the $399-499 range, GAME changer!  Disclaimer:  I have no current plans to sell anything or make anything off this project.  (Don't know what the forum rules are regarding this.  If this changes, I will make sure to ask and follow those.)  An ideal solution would be an ECU that plugs in, has the wideband controller already inside it, and falls into the above price range.  


This could happen, but not with a MagaSquirt based system.  I don't want to jinx anything, but I do have another tuner and board developer who has expressed interest in the project.  If this goes somewhere, it could be epic!  


The next solution would be a very clear recipe and roadmap for putting together such a system, and some decent starting maps/tunes.  Most of this will available just by following this thread.  Actually when I start the real work, I will start a clean side thread just for this.  I will link back here when I do.   


Well the mail has FINALLY arrived with my package of a dead 22re ecu, let the fun begin!!!  I am going to be busy the next few weeks!  I am sure you guys will be relieved to know!  Less posting, more doing HAHAHA!    

But Maineah please let me know if you want and I will post up a better explanation of the how's and why's of modern injection and tuning methods vs the old carbonated tuning and thinking school.  I had already partially written out a response anyways lol...     




Edited by thewanderlustking
Link to comment
Share on other sites

My motorhome is my hobby my friend. Travel and camping are what I like. I keep it tuned in the sense that it runs reliably and gets me to and from my planned destinations within the 12-15mpg limitation it currently possesses. Nothing too fancy or mind blowing mechanically here. 

Link to comment
Share on other sites

WME I know I know, I said I would behave and not post so much...  But yeah this is why I am trying to save so much in other areas of the project.  This is where is gets exciting for me!  


I started tuning in earnest when I was bet I couldn't turbocharge and double the HP on an engine on a budget for some xxx dollar amount.  I think it was a grand.  (But that was also 20+ years ago.)  I hit the target with lots of budget left over, and I was HOOKED!    

Link to comment
Share on other sites

30 minutes ago, Scott iv said:

My motorhome is my hobby my friend. Travel and camping are what I like. I keep it tuned in the sense that it runs reliably and gets me to and from my planned destinations within the 12-15mpg limitation it currently possesses. Nothing too fancy or mind blowing mechanically here. 


Same!  Just sadly haven't been able to do any travel or camping lately...  And then add in tuning as an even bigger passion!  Makes it a little, messy LOL!  


Messing with Toyota's "near perfection" in this would be risky if it didn't come so easy to me.  My boss is frequently amused.  I hate AC work.  He will watch me get frustrated and toss the towel to him to sort out, but then whiz through much more complex drivability problems he would have preferred to kick to the dealer.  Lol in fact usually when I say "Send it to the dealer" they know it means it isn't interesting enough of a problem for me to really get excited about.  Or even worse, one I will have too much fun working on and they won't be able to pull me off of!  Or charge accordingly for...  


Yeah the house wiring, integration the solar, and all those functions, like how to even turn on my hot water heater in the RV, I haven't quite figured out yet.  LOL.  But it is FUN to learn and if I can't go camping right now, I am going to tear into learning all of that!   


It could all backfire.  The wife wasn't nearly as amused with my last toy as I was....  I see added reliability, she sees "Oh you are making adjustments AGAIN?!"  Well yeah, I added in x-part and now I can make it spit fire, of course I need to make adjustments....  I had a little 2.0L 4cly VW engine that from the factory was only 90hp.  Shortly after I sold it, it was dynod at 350hp.  At one point, it was making 37mpg!!!  It was probably sitting around 200hp back then, and it had a much smaller turbo.  By the time it was getting close to that 350hp, MPG was no longer a concern.  Still, it was getting about 24mpg.  Power does not have to come at the cost of economy.  But take it past the magic efficiency of a perfect setup for the engine, and it will start to cost to see those gains.  


Well I have dinner to make, and a factory Toyota ECU to open up and explore!  And a new soldering iron to try out come to think of!  


Plus some nice new headlights to put in.  As much as I REALLY wanted to, I am being good, for now, and going with modified H4 halogens.  I might get silly and build some HID projectors for it to gain some MPG...  I think I still have a box of them in my parts storage....  They are more energy efficient.  But I have converted almost everything else to LED, so I will likely still be ahead of the game.  I need to convert my front turn signals to LED though now that I think about it.  Hummm...  I might already have some of those on hand to play with.


I will take pictures and start documenting some of these upgrades, perhaps even giving them their own little DIY threads.  I already have some REALLY cool upgrades I regret not documenting well...  My absolute FAVORITE one so far being my tire equalizer system!


Funny thing, dually equalizers actually improve MPG.  And I did it out of cheapness so I could use an automotive 4 tire TPMS system.  LOL!  


Link to comment
Share on other sites

Lets talk about what DIY's you guys want to see!  Input is welcomed!  I have a few in the works.


Already going:


1)  Headlight upgrades.  Basic, but perhaps some tricks that others may not know.  Honestly reading a DIY would have made this ever so slightly simpler for me to do too.      


2)  The Engine management Thread.  FAR from basic, but an interesting exploration.


3)  I will be doing a DIY on my approach to upgrading, or changing out my taillights.


Possible ones:


1)  Rearview mirror monitor upgrade.  More than simply a backup camera, this is operation whenever the truck is on.  It also puts lines up when in reverse.  Mine also has a forward facing dash cam.  Mostly done, but easy to get pictures of the process.    


2)   Cleaning engine bays.  Basic again, but I do take a different approach and use some tricks I have learned over my years of wrenching on cars and trucks.  


3)  My tire equalizer and TPMS system.  


4)  Upgrading other lights to LED.  


I will edit this with links, and add more ideas as I come up with some.  Please let me know anything else you guys want to see.  Some I will likely just post up as posts here in my primary "build thread" but others will have their own dedicated threads.  When I tear into the interior farther, that stuff I will just have here in this thread.  And I will add an index into my first post here also for simplicity sake.  I enjoy writing, so might as well pass some of that one.  Least I can do for all the help you guys have given me!!!  


Yeah, I sorta suck at the whole RV-ing house side of this.  But I wouldn't hesitate to yank a head, and replace it in some random parking lot out on the road.  BTW, brand new heads for out 22RE engines are only $200!  How crazy is that?!  Probably because these things never blow up.  Man would I like to have one sitting on the shelf though.  Oh and a whole engine rebuild would be pretty cheap too.  Haven't looked too closely at it, but easily under $500.  

Link to comment
Share on other sites

I don't think you under stood what I was saying yes FI is far more efficient than any carb. My point is aero dynamics of a class "C" sucks you can make your 22R/RE more efficient but the results are not going to be dramatic it maybe more fun to drive with some extra power I don't dispute that but it's not going to get 20 MPG. Now, I was in the auto trade for only 38 years during that time was the slow change over to FI, I taught continuing education for Bosch  so I do understand how it all works. If you look at the fuel figures the only things that get reasonable millage are class "B"s they are small, light and good attempt at aerodynamics that is the key. One of the biggest issues with a class "C" is the bunk roof over hang that's a big part of the "brick issue". Go for it have a ball it will be a lot more fun to drive with the extra power. 

Link to comment
Share on other sites

The power alone for sure will be nice!  I do still think that upgrading from the technology of the ‘80’s Nippondendo/Bosch L-Jetronic clone will see a significant mpg increase.  Yeah, I’m going to hit the aerodynamic wall at some point and may have to make choices like removing the roof mounted Coleman sail to get further. 

But this is about improving the overall experience and not just a crazy mpg number. At some point I will need make concessions to that.  Keeping the comfort of the ac, without a more suitable solution, will win over an extra few mpg. 

Technology has come a long way in the 35 + years since that Toyota fuel management  was designed. While I am going to fight aerodynamics of a brick, I still think we can see mpg numbers above 20. I don’t think the limit is set at 15-16 mpg. 

Whatever the case, it is going to be fun to try!  

Most of the parts have arrived, just waiting on fuel injectors and the new dizzy. Neither of which really are stopping forward movement on it. I have the spare/donor ecu apart on my workbench. 

I wish I had the patience to wait and extensively test one item at a time...  It would be interesting to try some tricks, like just changing the injectors out. I probably will at least experiment with running the modern high-z injectors on the stock Toyota ecu to see if that would work. 

Now this won’t work without adjusting the AFM spring tension. Or the same size injectors as stock (mine aren’t). So this mod alone done without care, would actually be a detriment to mpg. 

Link to comment
Share on other sites

Something else to keep in mind on mpg some people who post mpg are delusional and honestly believe they are getting 20% better mileage than 100's of other similar rigs.  Then their are those who in an effort to impress lie about their mpg.   


Musing on it,  the front of a toy is ball park figure 60 sq ft,  the frontal area of a roof air is about 3 sq ft or less than 2% of frontal area.   If eliminating the AC equates to a 2% increase in mpg,  I would much rather be cool when parked than have a 2% increase in mpg when driving.  And I am very skeptical of a 2% increase and would guess it would be negligible.   Also never saw any wind tunnel testing of an RV which would be interesting. 


Looks like a fun project,  I do not have much to offer but will enjoy reading about your efforts and effects. 

Link to comment
Share on other sites

I kept the “BS Factor” in mind and tossed out any crazy outliers of the average. My Google-fu came up with an average of 14-16 on the Toyota RVs.  The small number of references to Mini Cruisers, were actually on the higher side. 

the reason I don’t think aerodynamics are the big factor here, is the references to Pickups and 4 Runners with the 22RE in them only gained 1-2 mpg for an average of 15-18 mpg. Obviously they have a fair bit less drag to contend with. 

Link to comment
Share on other sites

  • 3 weeks later...

I finally did some exploring with a hose to find the leak.  While it traveled a bit inside, I didn't get a leak until hitting the area right around the ac unit with the hose.  I was sure it was coming from a different spot further back...  That area stayed dry though.  I think this is good news?  Whatever the case, the AC unit needs to come out to fix.  I have a new gasket set for it on the way.  I am itching to really dig into the interior, but I HAVE to get the leaks 100% sorted out first.  Once that is done, fixing the ceiling will be next.      


I now have 7 matching wheels and a spare tire holder!  I did the front hub conversion, it went really well.  That led me into a new problem to solve though.  The front brakes are bigger and the calipers take more fluid.  After several days of research and digging, I finally found the tidbit I needed.  The master cylinder on the '91 donor is actually supposed to be a 1" bore.  The brakes need a flush something bad.  I ordered a new master cylinder with the correct size big bore.  When I put that on, I am also upgrading to DOT4 and super flushing the system out. The front rotors could use a cut and some fresh pads.  But for now it will be sitting, so might as well wait on that.  Should be a nice brake upgrade though.  


Backup camera works awesome!  I have most of the cab electronics happily sorted out now too.  I just need to finish a few small details up, like getting a couple trim bits back in.  I also am going to install a dedicated 12v socket by the fuse panel on the drivers side and underneath the kick panel for the backup camera/mirror system.    


We have an outing tentatively planned for late October.  So I have a good 4 months to make serious progress on it, and then go for a couple shakedown runs.  My next and biggest push will be the leak and ceiling repairs.  Most of the rest can be taken in smaller chunks.  But this job will take the biggest weight off, once it is done.  


The next "project" though is to finally take some proper pictures, especially of the interior.  I don't think I have taken ANY pictures of that yet...    

Link to comment
Share on other sites

It's not just Toyotas no RV gets good mileage. It more than any thing else is the frontal drag of the over hang many RV's suffer from this. Even ones with a good bit of power still only get maybe 14 mpg. Just look at the figure for say a Sprinter with no over head bunk it's pretty dramatic.

Link to comment
Share on other sites

On 5/16/2021 at 3:22 PM, thewanderlustking said:

I kept the “BS Factor” in mind and tossed out any crazy outliers of the average. My Google-fu came up with an average of 14-16 on the Toyota RVs.  The small number of references to Mini Cruisers, were actually on the higher side. 

the reason I don’t think aerodynamics are the big factor here, is the references to Pickups and 4 Runners with the 22RE in them only gained 1-2 mpg for an average of 15-18 mpg. Obviously they have a fair bit less drag to contend with. 

Well my older ones were constantly in the low 20's maybe 24 on the highway. Pretty much the same as my 2011 Tacoma 4L V6 4X4.(they were all 4X4's) When I tow my camper with the 2011 it is in the low teens.

Link to comment
Share on other sites

Posted (edited)

It is well known that the Toyotas have some of the best, if not the best, gas mileage numbers out there, ever.  40yrs later and still nobody else has really come close.  So we are at least starting off on the right foot!  I watched another video last night on a Dolphin with the owner claiming 20mpg.  Obviously this is going to be under some sort of "ideal" set of circumstances.  But she also wasn't running her Dolphin on the organized and light side.  Who knows how much of the BS factor and rounding up might be in that claim though.  Are these 20mpg claims just really lucky people getting 18mpg, and rounding up slightly?      


Let's put this back conversation back into perspective.  Technology from the 1980's was just BARELY a few years from carburetors.  Simply put, it SUCKED FUEL.  We have plenty of reports claiming these guys can get 20mpg.  While I am a little skeptical of those numbers, it also isn't just one or two people claiming that.  There are a lot of variables we also don't know.  But the one thing we do know, nobody making these claims has done so after upgrading the old fuel management system.  That we KNOW is a major hinderance to good fuel economy.


Taking the approach of somebody who is not only a gearheed, but happens to have spent more than two decades building high performance fuel injection systems, I know that I can do significantly better than the system that is currently installed in the engine bay.  


For instance the stock system uses a narrowband oxygen sensor.  These can only "sorta accurately" read a fuel mixture of 14.7.  With a wideband oxygen sensor, you can actually adjust the fuel mixture WAY WAY down.  Depending on what the engine will be happy with.  I have seen engines that would actually run happily at cruise with the air fuel ratio all the way down to 17!!!  With one of our Toyotas with a house on top of it, probably not going to get it that low.  And if so, the stock system couldn't adjust fuel up quickly enough to be safe.  And I am reasonably sure there was minimal, if ANY, ignition mapping and adjustment.       


And comparing the old RV's and vehicles to new ones also doesn't tell the whole picture.  I hear the "But modern Sprinters still don't get great mileage" argument, but you're missing a BIG factor.  Weight.  Remember there are plenty of claims on our Toyotas already beating that 14mpg.  What gives?  Modern vehicles start of MUCH heavier with lots more safety systems, computers, ABS, airbags, and about a thousand other items added on top of what the older vehicles had to contend with.   


I can delve into this further, but the proof will be in the pudding as they say.  What I know for sure, upgrading the fuel management WILL make an improvement on the fuel mileage.  How much?  Who knows.  I will be happy if I get it to 20mpg, and ecstatic for anything above that.  Since we see outliers reporting 20mpg on stock systems, I don't think that is impossible to do.  


And again, it isn't just about the ultimate best MPG number, but the whole driving experience will be GREATLY improved upon.  


I know of a couple non-toyota RV's that were 'squirted and experienced pretty dramatic performance and fuel economy increases.  It is a safe bet that we shall see enough improvement for it to have been worth the experiment.  


Why haven't more people done this then?  Lack of experience vs cost vs return on investment.  There is no point to do this to any modern RV out there.  Voided warranties and all that.  Next, most people don't have the tuning experience to pull this off.  So having a tuner shop install such a system, would be in the thousands of dollars.  And then most tuners also aren't tuning for economy, so even amongst those with the knowledge to set a system up, it is still a pretty niche area.  The normal approach would also be to use a chassis dyno to safely dial it in.  Something that putting our RV's on would probably be difficult to try, if even doable.


And again, cost vs return.  If you were to eliminate all the above issues with a plug and play system that anyone could install, it would still have to be cheap enough to make a smart investment.  Lets be realistic, spending $3-6k to get maybe a few mpg and a couple extra hp, would take YEARS of constant driving to pay back.  It doesn't really start to make sense, until that price gets below about $500.  Get it down to $300, and I am pretty sure there would be some people here willing to try it out!


I have a TON of projects on the RV to tackle before any significant progress, or real proof of it, can occur on the engine management though.  At this point I still have some rear lights to tackle before it can legally be driven around.  And a roof leak to fix because driving it around with a grey tarp on it, I am sure would also get me pulled over...  Brakes need a little more work.  I haven't driven it with the larger front brakes yet, but I am sure they would feel off and a tad mushy/weak with the stock master cylinder.  After all of that is done, it won't be driven any significant distance on the current tires.  They are over 10yrs old and showing it.


I have everything on hand and only had to purchase some oddball parts like the extra distributer for experimentation, injectors, and some other small odds and ends.  So for me, it isn't an expensive outlay of funds.  Once I fire it up and get it happily running on the MegaSquirt, I might spend some actual money on a Speeduino ECU.  The MegaSquirt option is going to be a little pricey for most to be interested in trying out.  But the price point on a Speeduino ECU makes it a lot more approachable of an option.


Anyways, 40yr old technology vs current technology.  There WILL BE improvements.  My cost to do it for myself, will be small enough to have been worth it.  And I suspect I can put together a recipe or maybe even a full package to make it beneficial for others to try also.  

Edited by thewanderlustking
Link to comment
Share on other sites

 Interesting.......I've often wondered why you don't see anyone installing newer drivetrains in one of these.


 I have no doubt a person (with the knowledge)  can improve on the 30-40 year old technology but new technology would do it for you.

Link to comment
Share on other sites

Posted (edited)

It is a LOT OF WORK!!!  


Some have installed newer drivetrains for sure.  Linda recently posted some pictures of an LS powered Toy in fact!  Probably much more common to do that, than what I am doing.  But no, an engine swap or drivetrain swap is not a simple thing to accomplish.  I have done plenty in various performance tuning situations.  Anything like that though really requires a team approach.  Unless you have extensive knowledge of the platforms and parts in play...    


So to go that approach, the first thing you look for is what options did the factory drop in later on.  In our scenario, there are some V6 swaps that pretty much bolt in.  Next thing is opportunity.  If you have a free LS engine, or insert whatever other option you do have on hand, then the cost to install that becomes less of an issue than going and buying something random, or specific to swap in.  Even a bolt in option is going to take work, and cost something in additional parts needed to actually make it work.  


I am a purist.  If it is a VW, I put a VW engine into it.  A Toyota, gets a Toyota motor.  A Lexus engine in a Toyota, would be acceptable.  But true cross platform swaps, bother me.  I have seen too many nice cars ruined by swapping whatever junk on hand into them.  An old Jaguar with a chevy V8 comes to mind.  This is just my own, tweaked sense of reality though.  I have a knack for taking the underdog power plant, and making it better.   I think they can be nicely done, but there will always be compromises made.     


An almost brand new modern driveline would also do it for sure.  But it also gets much harder to install with all the modern emissions controls and networked computers needed.  And a motor and driveline for an RV need slightly different configuration and tuning than a stock modern setup from say a Tacoma would have.  With some study and effort I am sure the right combination could be found.  But how are you going to get older systems, like the tach, working?  So even doing this, compromises would be made somewhere.      


But in these Toyotas running the 22r, 22re, 22ret engines, we already have a pretty bulletproof engine willing to take much more punishment than it should.  And a platform that already has beaten out many modern platforms for fuel economy, on an outdated fuel management system.  


 So instead of days to months worth of pulling out heavy motors and transmissions and then trying to get the new stuff in, sorted, fitted, and running, just tp end up again with older stock and untunable engine management... I just have a few days of reconfiguring a MegaSquirt and making up some sort of adapter harness.  This is very light labor work.  Brain intensive, sure.  But physically easy.


In all seriousness, I have probably put as much time and effort into the posts here, as it will take me to get this running on the new EFI!  My only roadblock is another project sitting on my workbench I am supposed to tackle first.  LOL!  


But hey, I am making decent progress on the RV project as a whole!  Most importantly, the other half has accepted it as "my project" and she has finally stopped trying to sell it out from under me.  As long as the big house projects don't get forgotten...      


And back to the whole recipe concept.  So while I could fit a more modern driveline (if I could do so before she got fed up with the project) what benefit does that serve anyone else?  Sure, I could claim 40mpg and call it a win!  But could anyone else repeat that and verify it?  Nope.     

Edited by thewanderlustking
Link to comment
Share on other sites

Another reason why much more modern drivelines aren't really considered.  So you have a computer controlled transmission and engine that actually need to be networked together.  Plus a bunch of other systems that also rely on that information.  While most of those aren't going to be used in a situation like this, eliminating them does throw errors into the systems you still need.  Sometimes these can be fatal dealbreaker errors that put the needed systems into a limp mode.


While you could potentially then dump the factory controls and again go to a standalone system, you then loose any real benefits the factory system had to begin with.  And modern engines contain lots of extra controls like variable cam timing that the inexpensive standalone won't be able to deal with, or if so require much more work and tuning to get anywhere near close to what the factory had already done.  


Back to the older 22re driveline.  When we are starting off with an already impressive motor known for good fuel economy, but are dealing with 30-40yr old technology controlling it...  I think the ease at which we can improve on that FAR outshines anything a more modern driveline could accomplish, with much less effort going into it.  

Link to comment
Share on other sites

There's a guy in Bend who has been building motorhomes on Tacoma's for years. There's a new company in Reno also building motorhomes on modified Tacoma's with a composite coach body. Very expensive but beautiful. For slightly older swaps, there was a Sunrader on a Chevy 4x4 that traveled all over South America. I saw it driving down the road in San Jose California one day. Man it looked good. He sold that one for quite a bit even after all those miles. I saw a Chinook camper also on a Chevy near me. Also fabulous. And of course there is the Tundrader. Sunrader on a Tundra. Newer chassis are used all the time. The limitation is the few with the skill to do the work. One other drawback is probably the price if you want a new truck. When your base costs thirty grand before you tear it apart it's got to make you hesitate.

Linda S

Of course lets not forget Bajadulce's conversion to a 1995 3.4 liter 4x4. Epic

Link to comment
Share on other sites

Well that is cheating!  And MOST DEFINITELY the way to do it LOL!  I was assuming he was talking about an older motorhome and chassis, with modern driveline as in engine/tranny, and supporting wiring/ecus. 


But yes it comes back to the same thing.  Finding the few with the skill to pull it off, and having deep enough pockets to afford their work!!!   


Looking at the fuel economy side of things again though, a modern Toyota chassis (complete vehicle etc) is still going to be carrying around a lot more weight than an old 1986 pickup with the RV shell would be.   I think that is the biggest reason why we aren't seeing new RV's getting silly crazy MPG.  And obviously at some point, aerodynamics do come into play on the older, and newer vehicles.  I stick to my conviction though that 20mpg, if not even a little better, is possible on these older chassis.     


Link to comment
Share on other sites

Toyota was one of the first to use ported electronic injection they were way ahead of the game with a system that was on top of it, the basics are still used today on just about every thing. If it ain't broke don't fix it. The gain will not be worth the effort. You can turbo charge a brick but it will still be  a brick. Seriously check out the numbers with RV none of the ones with an over head bunk get decent millage even with modern systems and more efficient engines. Don't forget the coefficient of drag increases with speed "I can't drive 55" remember that?

Link to comment
Share on other sites

Toyota was FAR from the first to use that system, the Nippondenso is actually a clone of the Bosch L-Letronic system that was first seen in 1973.  Fiat was using that system in 1980.  BMW probably beat them all to it.  I want to say the 2002 was the first car to market using it (L-Jetronic), but I can't find anything to back that up.  Now Toyota may have been the first using it in an RV.  But let's be very clear, Toyota did not do the work and invent this revolutionary system.  They licensed it from Bosch.  


The D-Jetronic was the first true Multipoint electronic fuel injection system and I believe it was first released in 1967 on the Volkswagen Beetle.  But, Bosch had released mechanical multiport fuel injection way way back in the 1930's on the Mercedes 300 whatever it is..


Not sure how many standalone engine management systems you have installed, but I have easily done well over 150 installs and tuned countless more.  I have spent maybe $100 tops on parts for this experiment/project.  I have a couple grand sitting on my shelf in additional parts, like the ECU and some other goodies. just collecting dust with no place to go.  I am not going to sell it on eBay, because I couldn't get it all back out.  


I have converted several Bosch L-Jetronic systems over to standalone, and already know just how restrictive the system is.  Simply removing the Air Flow Meter on these systems, increases MPG and horsepower.         


The fuel injectors are antique technology and don't atomize the fuel well, loosing both HP and MPG.  


And the list goes on and on.  I have gone over it in (probably painful) detail.  


If I see a small 2-4mpg increase, I have already proven my point.   But it isn't just about a 2-4 or better mpg increase.  The truck will drive better.  It will have a snappier more responsive throttle.  I can adjust the timing in 3 dimensions, and shift the torque curve to a more ideal spot for the extra weight and different driving circumstances our RV's see.  


High elevation?  The L-Jetronic and Nippondenso systems don't actually have any real barometric correction.  Translation, they suck at higher altitudes.  This system will have full time barometric correction.  Not that I plan on driving up Pikes Peak, but I could...  


And all of this is still BEFORE I potentially put a turbocharger on the truck.  Even doing that, won't cost me a fortune.  I already have at least half the parts sitting on the shelf, with nothing better to do with them.  


And a turbocharged brick is still faster than a non-turbo brick.  


Now I agree that if I was spending thousands and thousands of dollars to just prove the point that I can increase the MPG a few numbers, the gain wouldn't be worth it.  As for effort invested, I enjoy doing it.  And even if I am wrong and there isn't a significant difference in the MPG numbers, every other benefit of this upgrade, far outweighs the effort and cost to me.    


Repairability alone is a win.  None of the Nippondenso parts are really cheap.  The airflow meter ALONE costs more than I will probably pay for the whole setup (pre turbo, obviously that will cost something if I bother taking it that far).  


Yes there is a point where the aerodynamics of a big brick will significantly hinder more improvements.  We have at least a little ways to go before we get there though.  



Link to comment
Share on other sites

en.wikipedia.org/wiki/Jetronic. Japan was on top of it the US still had their own and it was just shy of worthless they eventually went to ported injection. MB had the for runner of fuel injection based on their diesel system it was mechanical. I taught EFI back in the early days at a community collage. Go big time with a Kinsler system if you want performance.

Link to comment
Share on other sites

Cubs Mod Shop in Colorado

and Elevated Overland both have done some impressive Chinook/Sunrader swaps onto new trucks.

Link to comment
Share on other sites

Posted (edited)
On 6/8/2021 at 9:17 AM, Maineah said:

.... Go big time with a Kinsler system if you want performance.

lol I’m kinda thinking that wouldn’t bolt on too easily....  And the price tag, holy $#!+ Batman!!!  And I suspect doing that would drop my mpg to 3-4..  😂😂😂

Boy has fuel injection come a long way in the past 40yrs!  MegaSquirt changed the game for sure. And now Speeduino is doing it all over again!  As I have mentioned (probably here and definitely in the other thread) the plan is to get it up and sorted on MS and then to think seriously about trying out a Speeduino ECU. Mainly because I haven’t used it yet.

But a Speeduino could be cheap enough to make it a worthwhile experiment for somebody else to try out.  The ecu would be about $200 for a diy. Maybe $400 built and tested. Add in the cost of any support parts like injectors, wideband, and randoms. 

Anyways moving on LOL!  I’m getting the mess cleaned up, and putting things together, and finishing some random projects on it this evening. I’m going to try to get some interior pictures taken and posted shortly.   

The big project tonight is to see how long the Coleman ac takes to cool the interior down. Let’s see if it is even worth trying to save.

Edited by thewanderlustking
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...