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Posted

This is going to be an interesting experiment!  I have made a few comments that I think I can greatly improve on not only the power output of our little Toyota 22RE motors, but also the fuel economy.  And boy did that start some discussion and even some controversy!  I am not going to continue that discussion here.  This is going to be a "proving it!" thread!  For sake of this thread, I will restate and go over a few things mentioned elsewhere.

 

My goal is simple.  I want to improve the power output from this little workhorse, and I want to do so without costing precious fuel economy.  I hope to even improve the fuel economy significantly enough to prove that it is possible to have both power and economy.  

 

Targets?  Realistically, I don't know.  So let's just call them "hopes" instead.  

 

At the minimum, I know that with tuning alone, I can get the stock setup to have more power where it will be more useful to us.  That isn't worth much and no gains from that are going to be easily quantifiable with numbers I can post here.  So I will go deeper from the beginning and fix some issues and limitations the stock engine management has.  This first stage though will still be easily reproducible.  This thread will hopefully end up as a recipe on how to get there!

 

Stage 1:  With a fairly stock setup, at a MINIMUM I can repeat the baseline fuel economy numbers of  12-15 mpg.  But I honestly believe that we can easily get this to 15-18 mpg.  In the tuning world, stage 1 is usually limited to simpler bolt on mods.  Maybe exhaust upgrades.  I am most likely going to include a stage 2 or 3 mode from the beginning though, upgraded fuel injectors.  I will stay away from other more intensive modifications though.  

 

Goal:  I want this first step to be enough of an improvement that others would want to follow and repeat it themselves, without a large expenditure to get there.  15-18 would probably be that proof.  

   

Stage 2:  15-18 mpg.  I am again, going to hope for more.  If I don't get here in Stage 1. this is where I will pull out the stops and try more intensive mods.  I still want to limit this step to parts that are reasonably obtainable, almost anyone can install, and repeatable.  I am pretty confident I can get the motor to this point without adding boost to it.  If I get to the 15-18 mpg in stage 1, I will look to add 3 more mpg to this one.

 

Goal:  Getting to 20 mpg without boost.  Fuel pressure bump might be needed, and other more intense ignition upgrades are likely.    

 

As much as I may want to, I won't cheat at this point and heavily attack weight or aerodynamics to get there.  I will be cautions of adding too much weight though as I do have to make repairs in the house before this is usable as a proper RV.  

 

Goal here is again to see enough improvement that somebody else can follow the recipe and be happy with the outcome.  

 

Stage 3:  BOOST!  Honestly, I don't believe we can see crazy mpg or performance gains without adding boost to the equation.  Stage 3 will depend on how far we have gotten already, without boost.  I would like Stage 3 to again be easily repeatable parts but that is where I run into some unknowns.  There are 3-4 turbo exhaust manifolds readily available, but they are all for the original type CT20 turbo.  I haven't gone too deeply down that rabbit hole, but I think the CT20 turbos available are all the same specs.  There appear to only be two styles, with some minor connection differences.  

 

I won't set goals here yet, too far away to have an idea at this point.  Other then again, I hope to do this with off the shelf parts.  I would prefer to do this with a T3 turbo, but no manifolds are out there for that one.  BUT the narrow range of options for a CT20 setup, do make it friendlier for others trying to repeat the recipe.  

 

Stage 3 will cost money though.  So it may not happen soon, if at all.  It will depend on how far I get in the first stages.  

 

Well the first goodie for this is now opened up and sitting on my workbench!  I have a dead 22RE ecu to use to start my experiments with.  Another goal for the first stage is, a system that can be changed back to stock in a couple hours tops.  To do this and make it repeatable for others, it needs to be plug in.  While making a harness is work, it is still easy for me, I know that is NOT the case for most.  

 

For now, that is all!  I will post some pictures up once there is something interesting to show.  Hopefully you guys will enjoy the journey and find something useful here.      

 

 

 

    

 

 

 

 

     

 

 

  

  • 2 weeks later...
Posted

Alrighty making good progress!  Most of the parts have arrived now. Not waiting for anything critical.   
 

Prepping the spare factory ecu for a breakout box. For the moment, going to focus on quick plug and play.  But not worried with fitting this inside the factory case yet. That will come later.  
 

I’ve got most of the research part done. Wiring up the plug and the mods needed for the ecu etc.  I only need to figure out how the cold start injector is wired up/works. The L-Jetronic systems used a thermo switch. I think this is the same. If so, I can just leave it in play.  


 

Posted

On my moded 22RE there was an exact temp where the engine need a bit of "choke" to fire off. The thermo switch said nope, the engine is warm enough.

A parallel momentary push button switch let my thumb provided "choke" the engine for an easy start.

 

 

Posted

hellow  e  been a while since i been on here   on my oyther toyota 87 4wd xtra cab 22rec . i fixed the no  start                    cold below 40 deg .cold start.injeckter , iwired it strait to a line fuse to a togle switch . flipit on off hit key fires right up when cold cold . when not so cold turn hit key turn off fires right up . use this 4 years already.

Posted (edited)

WME and 5Toyota, that is an awesome hack, I love it!!!  And disclaimer: technical babbling about to follow...  

 

It is a catch-22...  I can easily program and tweak the cold start settings as needed on the MegaSquirt or Speeduino management platform and dial it to perfection.  Problem being, my Toy may never see true cold, or even get much below 50 to do so.  While I can easily do this if I ever needed to, the idea is a repeatable recipe for others.  Possibly, even a nice DIY package down the road.  In my years I spent doing standalone installs, I noticed that customers had more trouble with cold start and warmup settings than just about anything else.  

 

Since the cold start injector and thermo time switch setup (I believe) has no actual connection to the stock Toy ecu, I figured I might as well leave it alone and in play.   Humm, maybe not...  Looks like I need to do a little more investigating on this and to go dig up some proper engine bay wiring diagrams.  Here are some diagrams of the ECU connectors from DIYAutotune's article: How to MegaSquirt Your Toyota 22RE  It is a super detailed article and covers about 80% of what I want to know.  Unfortunately, a few decisions were made in that setup that I don't feel are necessarily the best.  Each install has some unique choices to make, and one approach doesn't always suit all.  

 

   Overview-of-Toyota-Connectors.gif

For-the-22RE.jpg

For-the-22RE-2.jpg

Speed-Sensor.jpg

 

Anyways, mostly ramblings of a Mad Scientist.  There are some nice details in that article on injector wiring and other bits of interest (to me at least).   

 

And again, choices are made on each install and use scenario that are catered to that setup's goals.  With my main goal being an easy repeatable recipe to follow, my first approach will be a plug and play one leaving as much of the original Toyota wiring and engine controls in place as possible.  Ideally enough so that, in only a few minutes, one could swap the Toyota ECU back into place.   While this is defiantly possible, I am not sure how much effort I want to put in to make that possible.  Where do I draw the line?

 

Put it this way, by the time I modify the ECU case, sort wiring the plug, sort the other OEM engine controls, and am ready to plug in and do my first start, I could gut and rewire the whole engine fresh.  But doing that, it is also becomes impossible to go back and prove what individual components made the biggest difference in the battle for higher MPG.  

Edited by thewanderlustking
  • 7 months later...
Posted

So I have been really quiet on this thread for a few reasons.  Main reason being, the beast wasn't road ready yet.  We are mostly there now and it is finally street/dot legal.  Without being able to drive it, no point to do the swap especially since I want a before baseline MPG to go by.   Next, interest has come and gone as the wife has threatened to sell it a few times.  I have made good progress and she is finally excited about the project again though.  Finally, I have been working on a secret weapon.  A custom diy PNP ecu.

 

DIYAutotune makes a 4Runner/Pickup 22RE/22RTE MSPNP Gen2 Plug and Play ECU option that plugs and bolts right in.  At $799 it is expensive enough I would spend the extra and just get an MS3, but they don't offer a Plug-N-Play MS3.  

 

By accident, I discovered that a Miata ECU is almost an identical case and same size internal footprint to the 22RE ECU.  I have a prototype PCB sitting on my workbench to take advantage of this.  I stumbled across some minor issues so far, but I don't actually need it to get an MS3 into the Yota anyways.  That project is momentarily stalled, but I have other options.  

 

Tonight I spent some time under the dash to determine if I can simply mount the MegaSquirt I have, in the stock location.   It won't fit there without cutting a hole in the kick panel.  Or leaving that off.   Neither option appeal to me.  I would be okay with making the hole, but I couldn't get to the plugs and SD card slot anyways, without removing the panel.  My MS3 is setup wirelessly, so this isn't really a big issue.  But I have been loath to cut and drill into anything in this interior, it is so nice.  Also, I want it all as invisible as possible for now.  

 

Maybe I will get a laugh and mount the intercooler out on the bumper Shakotan/Bosozoku style.  But for now I am going to just keep it weird and mostly 1980's vintage looking.   

 

Realistically, this leaves me with three mounting locations.  Behind one of the seats or in the radio slot.   The behind seat locations are simple, but with two drawbacks.  Long wiring extension harness runs for the ECU and gauge, and a long run for the vacuum line.  Swapping out the 1 1/2 din radio for a single, so I would have that space.  Short runs of wire and vacuum line.  But future "goofing around and experimentation" would be a lot harder than just flipping the seat forward.  

 

I would prefer to use the space behind the passenger seat for storing the emergency roadside kit and first aid kit.  But the shorter wiring run for the main harness and vacuum line is better.

 

The best location, is still the factory one...     Keeping it hidden underneath that kick panel would be ideal.  There is a way I can pull that off.  I need maybe half an inch of depth.  I think I have enough room I could cut out and make two Z brackets to inset mount it the half inch or so needed.  While I have to do some body sheet metal cutting for this, I am more okay with that than cutting the kick panel.  

 

While not a horribly expensive problem to solve, this last location still leaves me with enough length on my DIYAutotune wiring bundle to rewire the whole engine later on.  I think I might have sold myself on this last choice.  

 

Anyways, all I have left to to do in preparation before the swap begins, is to make an extension/adapter harness to plug from the factory wiring into the MegaSquirt.  And a bracket if I go with the last choice.  With some careful and creative cutting, I might even be able to utilize the factory sheet metal without making a bracket.  That will take some thought and planning.

 

Oh, and verify the timing first.  Wait a minute...  !!!  I think I might actually know what is wrong with the beasties lack of power!  Alright time to go poke at a couple ideas and look at my threads on that. 

 

          

  • 3 weeks later...
Posted (edited)

Picture upload time!  

 

I sat in the truck for a while trying out different locations, and turns out it fits underneath the radio console pretty nicely.  More hidden would have been nicer, but it isn't too obvious here unless your shining a flashlight at it to take pictures...  It can slide back further and I still have the option of putting it inside the radio console too.  But it is going in this general area for sure now.  

 

Ugh I need to do something with those wires in the conduit.  They look horrible.  I think it is the rear speaker wiring.  That is all getting upgraded here shortly.   

 

76113EBD-9618-4B8A-9F5A-36262FB4EED6.jpeg

 

So once the location was sorted out, time to figure out the harness!  

 

AF4F09A6-AA33-4386-987E-A8275F9BDEB3.jpeg

 

Soldering these up is isn't really hard, but it is tedious and takes a good bit of time and care to do.  It would not really be a practical recipe for others to follow.  But if somebody wanted to install an MS3, its probably the best way to do it.  There are plug in MS2 ECUs though.  And this adapter harness means that I can try out some different options down the road.  

 

3221B1D4-264E-497F-92AA-F30E242DA877.jpeg

 

The bottom of the ECU plug was the harder part to solder up.  The black wire on the right is for the oxygen heater ground.  I swear my o2 sensor was a 1 wire, but whatever.  It will use the dummy case to ground it and keep the noise out of the MegaSquirt.  This narrowband sensor won't stay in her for long though.  The factory board is conformal coated, likely with a lacquer.  So it took a little effort to burn through the coating.  On the bottom I ran the iron hot and pre tinned/blobbed on solder.  

 

AA2EB676-91CF-4E63-9998-D181234FC62C.jpeg

 

The top of the ECU plug was much easier.  I left the pins soldered into the board for support, but soldered to their legs.  Here I had to scratch the conformal coating off the pin legs with an xacto knife.  I wired up the injectors like Toyota did with two channels, even though apparently they are connected somewhere in the harness and are effectively only one channel.  I can decide later if I want to separate them in the harness.  

 

6E46790C-F385-43E4-8795-81B77BEF953D.jpeg

 

Here is where I had a lightbulb moment!  I ordered some terminal strips off of Amazon and used the case as a breakout board.  I can use this space as an easy to get to and reconfigure stuff area, without taking up much actual space in the truck.  I don't need to get in there often, so this is a perfect location.  But, it is also easy enough to get to in the factory spot.  

 

This allows me to utilize stuff like the intake temp sensor in the air vane meter, then quickly reconfigure it and wire in a different sensor when I remove the vane meter.  Same with the coolant sensor.

 

I staggered the strips so I can also put some strips on the inside of the lid in the future.  This will be needed for the second MS3X Expansion plug.  When I start getting into deeper aspects of the project, like putting individual coil packs in there, I will need a clean and simple way to add in stuff like that.  

 

The red loop is because the Toyota EFI fuse is 15 or 20 amp.  I need the switched feed for the MS to be protected with a 2 amp fuse.  Or breaker.  I have some aviation breakers I will likely utilize one of. 

 

4C918BDA-4CE7-4607-A273-F0804688CE3B.jpeg

 

Wiring is all finished at least!!!  Other than adding in the breaker or fuse...  I will probably drill a hole in the case side frame to mount the breaker.  I do need to make a quick cutout for the wire bundles too, as the lid will be going back on.

 

There are 4 tan wires going off in a different direction.  They are for the Perfect Tuning gauge.  I have the breakers and the room, I will likely utilize another one to power and protect the gauge.  

 

As for the messy bundle, I will use aviation wire ties to clean that up.  Once it is ready to be tucked up and run.  They stiffen the bundle considerably, so I want it run first.   

 

3183E8B6-402C-49F2-8ABC-2470CBA87E75.jpeg

 

I have not internally modded the ECU yet.  I need to undo some older mods and make some minor changes.  I will get that done in the next couple nights.  Once everything is done, the actual install and fire up will probably only take a few minutes to do.  

 

I will do a couple more "preflight checks" and verify everything then warm the truck up on the factory ECU.  Once warm, turn off, unplug factory ecu, plug in the adapter harness ECU, and we should have it running.  I want to bypass the cold start up on MegaSquirt.  It will let me reverify timing and are sure timing control is working without adding warmup issues to the mix.  

 

I have the brakes to still get sorted out and a couple other small details.  I am probably going to pull the downpipes and patch a small hole it has.  When I have it out, I will add in a second o2 sensor bung for the wideband sensor.  The weird factory sensor can just hang out and plug its odd little hole...  I can probably send its data into the MS too if I want.  

Edited by thewanderlustking
Posted

What you need is "split loom" for your wires it is available in various diameters. It has slit in the side to get the wires in so it's after the fact very easy to work with standard scissors will cut it.  

Posted

Used split loom many many a time!  It’s “quick and dirty” lol. For interior runs though nothing says I have perfection issues like using aviation lacing. And I have the supplies already on hand, so it’s free.  Free is good!  
 

Where I am running it, behind the blower box and above the drain tube, the space is pretty tight. The unsheathed wire bundle secured with ties will conform nicely and easily to the limited space. And once tied, it will stay where I put it. 
 

There is a practical reason for it too. In the case of damage like fire say from

a short, it limits the area of damage. And allows it to be quickly inspected. 
 

But mostly it looks cool, and I have it.   So it will only cost me about ten minutes. 

  • 2 weeks later...
Posted

I used lacing too for years until I discovered split loom! Nice neat wiring by the way good job! I bought a bag (like a shopping bag) full of those barrier strips for like a buck still have couple of pounds of them!

 

  • 2 months later...
Posted

Thank you Maineah!  

 

Heh, you remember those god-awful bright neons split looms from the late 80's early 90's?  Lol I probably have permanent mental scarring from that stuff...  A whole lot of modern cars make use of the normal black stuff these days.  I will use it in the engine bay whenever it matches the OE stuff.  

 

Progress in the 'squirting department has been slow...  As of tonight though, I "SHOULD" be finished with the other projects that were getting in the way.  -=knock on wood=-  Wheels are back on, it is ready to air up the tires, take it off the stands and ramps, and go for another shakedown drive.  

 

Instead of patching the exhaust, I went with a new one with long tube headers.  That will be the next project to undertake, but I want to get a baseline with the old one first.    

 

I don't have a whole lot left to do before initial power up testing.  Unfortunately, what I have left is mostly heavy brain work.  I need to hunt down some maps for the 22RE, and then probably go through and completely rebuild them.  Also I am not really sure what changes I need to make for a big heavy RV.  Or if that changes my approach to tuning, and how.  

 

 

 

 

  • 7 months later...
Posted

Hey thewanderlustking! Any update with this pursuit? I see that DIYautotune is now offering the MSPNP2 if you send them a factor computer so they can use the connectors from it.

Very curious if economy gains can be had that would justify the upgrade. I have a freshly rebuilt 22RE in my 85 Sun Land Express. Before the rebuild the engine had a bad comp ring on piston 3 and that cylinder would only do 50psi or so. We would get 11-13mpg in this condition and it seemed to be getting worse. After rebuild best average is 13-14. Was hoping for a little more but the Express is 22’ and not the most aerodynamic of the toy homes I suppose. 
From some testing I know that cruising down the highway, even on level grades at 55-60mph, most of the time the O2 sensor goes to a rich reading. It’s just a heavy load for the engine I guess the way these 22REs are mapped. Wondering if this can be successfully remapped using the mega squirt and wideband to get a leaner ratio at this cruising load and maybe get some more mpg out of it without making too much heat.

Hope your project is going well and you can share more. Cheers!

  • 2 weeks later...
Posted

Well I had stalled on the MegaSquirt project due to trying to get the house livable/redone.  And failing at that.  And as of Today, I no longer own it.  But it went to my best friend who has put a TON of work into it with me.  And his first questions today were asking about continuing this.  SO it is still happening!  And in fact it is pretty likely to happen at a quicker rate now...  

 

First off if you want a "monetary return" to justify the expense, well it will take a LOT of miles to get paid back on fuel saved.  That is a math problem that hurts my brain even trying to think of a way to approach it...  Still, 13-14mpg is pretty low.  Now if you want to talk about "smiles per miles" it will pay off very quickly!  

 

I have done "a few" stabdalone engine management installs over the years.  I actually cut my teeth wrenching, learning how to hack, modify, and tune Bosch L-Jetronic systems.  For years the Bosch Performance Tuning book lived in the bathroom for light reading...  Anyways once I started doing standalone installs, I discovered two things.  Contrary to popular myth, there is almost zero gain to be had from being able to tune fuel, until you are forcing in more air.  The ability to dial in fuel is mostly an economy one, or preventing meltdown in a forced induction situation.  The power gains are mostly to be had from the ability to tune spark.  Even more surprising to me though was just how much the ability to 3d map the ignition, also can add to the fuel economy.  

 

The ignition system is where most of the gains in economy and also in performance will be found.  Economy and performance are also in different portions of the map, you CAN have both.

 

On 12/4/2022 at 4:28 PM, NHBoondocker said:

From some testing I know that cruising down the highway, even on level grades at 55-60mph, most of the time the O2 sensor goes to a rich reading. It’s just a heavy load for the engine I guess the way these 22REs are mapped.

 

This is actually REALLY interesting information!  What O2 sensor and setup are you utilizing though?  If it is the factory Toyota sensor, it is essentially a rich/lean switch and pretty inaccurate.  I could go into a small book explaining how narrowband and wideband sensors work, but I probably already did earlier in this thread hahaha!  If you are using a wideband, I would love to know what the actual numbers are!  

 

On 12/4/2022 at 4:28 PM, NHBoondocker said:

Wondering if this can be successfully remapped using the mega squirt and wideband to get a leaner ratio at this cruising load and maybe get some more mpg out of it without making too much heat.

 

You dump the OE system obviously, so yes it can be remapped and you can get WAY leaner in cruise.  Remember though you are able to also adjust timing and correct for issues there too.  An engine running where it wants to be, isn't turning into an inferno.  Whatever the case any MegaSquirt install is going to let you datalog and keep a good watch on heat.  On turbo cars, I have frequently utilized a warning light to monitor Intake Air Temperature.  If I am doing this, I usually have a warning light for coolant too, but RARELY have I seen those pop on. If that comes on, something has gone wrong.  Obviously this also depends on what temp you set it for...  

 

As I have gone over in prior posts, eliminating the old L-Jetronic/Nippondenso system is where a lot of gains will be seen.  Modern fuel injectors, quicker response times, eliminating the air vane restriction, better processing power, accurate wideband o2 sensor, all this is going to make some pretty big gains.  

 

There are plenty of reports out there of people hitting 20mpg in these guys.  Enough so that I think this is an attainable goal with a properly dialed in MegaSquirt.  I still think this target can be beaten too.  

 

On 12/4/2022 at 4:28 PM, NHBoondocker said:

I see that DIYautotune is now offering the MSPNP2 if you send them a factor computer so they can use the connectors from it.

 

I think they have a refurbished one in stock too ATM.  One of these options is likely the way to go for most people.  Honestly the internal ignition mods are a pain lol, even when you actually know what you are doing...  If I had started of with a PNP version, I would have plugged it in and tossed the OE ecu right out and just called it a day.  I would have had it running on a 'squirt long ago.  Instead I have to find some time to reverse engineer my current ECU back to stock, and then modify it to the VAST specs.  

 

Pause for explanation.  There are three primary MS processor groups.  MS1, MS2, and MS3.  There are then different operations systems for each of these, and also different motherboard versions.  I won't go into all of this here, its boring and not really relevant to this post.  Any version other than the MS2 in the MSPNP2, is going to require mods, wiring, and a really good understanding of how it all works.  

 

But I went with MS3 as I have a really nice one on hand, and I wanted the expanded functionality of the MS3 CAN system to use with a Perfect Tuning gauge.  Also I know MS3 way better than MS2.  For years I mostly tuned MS1 units, with only a handful of MS2 sprinkled in.  I went straight to MS3.  I don't know what version will get stuffed into this now...  I won't give away my MS3.  I likely have an MS2 kicking around I can toss in though.  This makes the most sense as I can get some pretty nice base maps out there for others to start with.  

 

 

 

 

 

Posted

Thanks so much for the reply! I saw the email and then got sidetracked and just read through it. Really interested to hear progress updates as you guys go.

 

I have done the math and realize its going to take a lot of miles to recoup the cost especially considering the time you put into the project! But.. you're completely on point with smiles per mile haha. The motorhome and engine specifically has really become a hobby for me.. I'm long past accepting that the money I'm spending on parts and tools is more for entertainment and self fulfillment than any sort of financial investment!! Also, the difference in range with such a small fuel tank would be pretty nice as well. I'm guessing you can get this engine running smoother and nicer starts with the more modern FI/ignition computer behind the scenes. Not that I'm going to complain, my engine starts very easily most of the time now and idles with just a very slight variation in RPM that seems to be associated with the system going closed loop and leaning out. 

 

It is the stock Denso narrowband, so yeah, not any sort of accurate reading. So I don't know how rich it's going at highway cruise.. but it's not stoich, and it's at least a bit rich.. Seems wasteful if it 'could' be run leaner with CHT/coolant temps maintained and enough power made. I get your point that most gains will  be had from ignition timing though. I wonder if it's worth looking into a different ignition setup over stock+mspnp? I would def go wideband O2 if I did venture to start this mod. I'd save a new injector setup for last as they're freshly cleaned/refurbed!

 

Side question, do you know if the stock ECU does anything to compensate for higher coolant temp? Reason I ask is I was battling high temps with this new engine (never above 220ish) and it came down to the new OEM fan clutch not engaging enough. I'm just wondering if maybe the ECU was going rich to try to counteract the higher coolant temps, and could be losing me 1-2mpg. After I got the clutch working properly (added higher weight silicone oil) I didn't have time to test mileage before it was time to winterize and put her to bed.

 

Thanks again for sharing your knowledge! 

 

Posted

I don't know how crafty you-all are, but this is an interesting ignition setup

https://progressionignition.com/

Posted

They didn’t seem to have anything specific to Toyota. And the MegaSquirt also does timing. 
 

Yaeh all systems compensate for coolant temperature. But it is going to be either when cold, so chances are something else was going on. 
 

Or you were getting on it more because it was low on power causing tryout fuel economy to go down. It’s hard to say, but coolant temp will effect fuel economy. 
 

So the ignition question...  Stock controlled by MS will get you much further along than just upgrading the ignition. The ability to control it in 3 dimensions gives you probably 75% of the gains. You will eventually reach a point where the stock system limits you. The Toyota cool is kinda wimpy, you might reach that point earlier. But once there it is a simple matter of swapping out the coil. 
 

And you can get silly and go Coil per plug too. That’s a bit harder to do and required it’s own thread lol. 
 

Toyota runs low impedance fuel

injectors. Most modern injectors are high impedance. If you were to go MS . That would be the very first thing I would suggest changing out due to requiring essentially a full retune. There are better economy and performance options for high impedance too. 
 

Now running the stock injectors through the resistor pack essentially makes them look like high impedance injectors to the ecu. I’m not sure why we didn’t do that on the few Toyota installs I did back in the day. But for some reason, we bypassed the resistor packs. 
 

There are cheaper MegaSquirt options if you wanted to DIY things a little more. 

  • 10 months later...
Posted

A bump for "this project isn't completely dead yet" updates!  As many know, my 22RE powered Mini Cruiser was passed on to my best friend Viktor.  I actually went and got a 1994 4Runner and have been living with it, and more importantly daily driving it for almost a year now!  

 

But the Mini Cruiser only lives a few miles from me, and most of the parts for the conversion are actually sitting on my dining room table right now.  I just went hunting through the garage and boxes and boxes of parts to make a pile of goodies.  I found two extra MegaSquirt ECUs I can choose from for this.    

 

A couple weeks ago I had my first ever REAL issue with the 4Runner.  (I am not counting the leaking radiator I had to replace, it was 30 years old and gets a freebie there lol!)  Fuel economy on it has always been a very steady but bad 10.5mpg.  A few weeks ago it starter feeling low(er) on power and it had dropped to 8.5mpg.  Then over lunch one day, it died on me.  Lots of shenanigans followed.  Diagnosing it WAS NOT FUN.  We were able to use a scan tool and actually get the codes out on the ECU and look at data PIDS.  So slow they were essentially useless.  Oddly, I couldn't get the blink code check method to work on this original ECU...   It sent us on a wild goose chase with bogus codes.  It went downhill from there with hours spent hunting with an oscilloscope, issues found, ecu replaced, and then suddenly truck is running fine on either ECU...

 

Anyways this has all led me to sitting here at the dining room table with the FSM, the electrical FSM, my diagrams for the Mini Cruiser, and making up new diagrams for the 4Runner.  The management for the 3VZE is VERY similar to the 22RE, just adding in a few more silly layers of over complication.  Enough so that there are no documented conversions, and only a few "I know a guy that did it" references...  My application adds in the complexity of the 4x4 system being integrated into the transmission and engine controller also.  So while I will be able to make significant improvements to power and economy, it is unlikely to be a simple or cheap blueprint to follow.  Ironically though it looks like the ECU for the 22RE and 3VZE will be identical other than programming...  The pinout wiring is different, but since I am not using PNP units, that's taken care of in the breakout box wiring anyways.  

 

 

 

 

Posted

Ouch!  10.5 mpg out of a 4Runner?

 

I have 3 of them,… the closest I get to that mileage is with my 87 22-RE, 5 speed manual, on 36” tires at about 12mpg.

 

My 85 22-RE automatic on 31s gets around 16-17 mpg

 

lastly my 93 3vze manual again on 31s with a burned valve on #3 still gets between 13-14mpg!

 

Of course my 19 Tacoma is the best at 21mpg…. (Yes I currently own 5 Toyotas)

 

So, I’m taking it the mini cruiser is 22re, and the 4Runner is 3vze?

 

Youre absolutely certain it’s electrical causing the poor mileage?

 

my 93 had the tensioner bearing go out on the timing belt and it slipped a couple teeth,… still ran fine, but completely crapped out for power.  I didn’t drive it long enough to see a change of mileage…. (Literally just home then diagnosed and repaired)

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