Weber Carburetor

[mulwyk]

The toyota engine has a very good, but complex carburetor. When it's new, it works great. But after 30 years or so, the little passages in there start to silt up, the choke sticks, and that amazingly complicated vacuum/smog system begins to fail. That's when it's time to either replace the old carb with a rebuilt unit or install a Weber conversion.

(You're more or less forced to de-smog the engine when you install the conversion kit, so if you live in a smog-test state you're stuck with using the original carburetor.)

We got a Weber conversion kit ($250 from Webercarbsdirect) for the 22R engine in our '84 Sunrader. There's several models of Weber carbs that can be installed on the Toyota engine. But unless you want to race your motorhome or you just don't care about economy, you'll be getting the famous 32/36 model. The 32/36 is Weber's bestseller, the everyday-driver workhorse of the Weber line. It's a two barrel carb: it runs on the 32mm barrel most of the time in economy mode, but when you push the pedal to the floor the 36mm barrel opens and gives an extra boost of power.

[WME]

Redline Weber carbs offers Ca legal Weber conversions for 75-84 20/22R in the 32/36DGAV series. They also have "off road" 38 DGES for a little more low end grunt.

[mulwyk]

Instructions come with the kit, and there's some great detailed info over at the Yotatech website. But here's a brief outline of the process:

(1) Remove the old carburetor and associated vacuum hoses and smog equipment. Label everything in case you ever want to return to the original.

(2) Install the new carburetor. Included in the conversion kit is an adapter plate for the intake manifold, a throttle adapter and chrome aircleaner.

(3) Plug the old holes. A plug kit from LC Engineering is handy, but you can simply buy the plugs one at a time as needed. I got a set of vacuum system caps from NAPA and used several.

The conversion took me most of a day to complete...experienced mechanics could, no doubt, do it much faster.

The engine started right up after the Weber installation and ran smooth as butter. Of course, I had to take it out and drive around town a bit to test the new carb. If driving the motorhome before had been like driving an overloaded truck, driving after the Weber install was more like driving an unloaded truck. I wasn't going to win a race or anything, but it just seemed like the power was more matched to the weight of the vehicle.

[mulwyk]

2000 miles later: the Weber is running great, very smooth and I love the extra power.

But, I had hoped the Weber conversion would improve my mpg's. That's not happening. I find my gas mileage is actually down a bit! I was averaging 18.7 mpg before the carb conversion (this is one very light, streamlined Sunrader, 18.7 is not typical Toyota motorhome mileage). Now, with the Weber, I'm getting a consistant 17.5 mpg. That's a 6% drop in mpg. Not a big change, but still, I'm a little disappointed.

Weber claims you will get the same or better mpg with the 32/36, and I think I'm driving the same way, but...??

[mulwyk]

Weber Anecdote:

Many Toyota motorhomers (motorhomeys?) have been to the Blackhills/Badlands/Mt. Rushmore area in western South Dakota. Coming from the east, the natural route is Interstate 90...a straight shot all the way from Minnesota to Rapid City. (A better route is US-14, less traveled, more scenic, it passes through dozens of charming little towns, many of which feature that wonderful midwest tradition: free camping in the town park. My wifes hometown, Miller, has one of the best free-camping parks on the route.)

US-14 joins I-90 just east of Wall, about 50 miles from the Black Hills. Wall is the gateway to Badlands National Park (keep your dogs close, the place is lousy with rattlesnakes)and, of course, Wall is the home of Wall Drug...an old-timey tourist trap in summer and, the rest of the year, a real ranch-country drug store.

Leaving Wall, I-90 plunges into the Cheyenne River gorge, passes a delightful cottonwood-shaded Interstate rest area, crosses the river at the tiny village of Wasta, and then climbs the infamous Wasta Hill. This is where I come to test Toyota motorhome power.

Wasta Hill is not desperately steep, but it's long, over 3 miles, and it leaves trucks and low-power vehicles growling and crawling at the top. My old '80 Odyssey would need a downshift to 3rd about halfway up and would be begging for a second downshift before the crest. Speed at the top= 30 to 35.

My current motorhome, a '84 Sunrader, before the Weber conversion, was a bit better (it's lighter than the Odyssey). We could make the top of Wasta hill at 40 to 45.

After the Weber carb installation, one of our first trips was out to Wasta Hill for a power check. It was a windy day, 25 with gusts to 30 from the northwest, so we'd be headed directly into a headwind climbing the hill. A good day for a power test.

I got the old girl up to 65 on the downhill run, passed the rest area, bounced over the river bridge, and we started the climb. Our speed began to bleed off at once. At the halfway mark, we were down to 40, I was preparing to downshift, but there was a truck up ahead doing maybe 30...pass or fall in behind the truck?

I decided to try for the pass and pushed my right foot to the floor: that's when I learned what the Weber could do. The engine tone changed from "aaaaaa" to "OOOOOOO" as the Weber's power barrel opened, the Sunrader paused for a second as if assessing this new paradigm, and then, OMG!, began to accelerate, 40,45, 50...we breezed past the truck and topped the hill at a record 53 mph!

Yes, up Wasta Hill, in 4th gear, against the wind...53mph. Ain't these Webers great?

[Bigdog]

witch weber carb did you purchase 32/36 DGEV or DGAV?

[mulwyk]

witch weber carb did you purchase 32/36 DGEV or DGAV?

Hi Bigdog,

According to my paperwork, they sent me a 32/36 DGEV with the kit. But really, I have no idea what that means. Do you?

[Derek up North]

DGV = manual choke

DGEV = electric choke (E = electric);

DGAV = water choke (A = aqua)

DFEV = electric choke (choke linkage rotates clockwise)

Source:- http://www.webercarb...uretors_s/2.htm

[WME]

Your MPG will go back to normal IF you refrain from using the new found power

Reality, also says that you may need to rejet the carb for your altitude. Know anybody with a fuel/air ratio sniffer?

[mulwyk]

Thanks WME, But Jeez! do I havta give up my new found power? Isn't there some way I can keep the power and still get great MPG? Maybe headers and a big bore exhaust system would do it. Or oversize valves with a RV cam. Or...rejet the carb? I'm at 3,300 ft. Would a carb rejet improve MPG without cutting into my new found power? I don't have any sort of mixture instrumentation.

[Bryan B]

add 2.25-2.50 exhaust and that will give you a tiny bit more power and help your gas if you can keep out of it. think your mileage is bad? I just installed a weber 38/38 in my 22r........ ouch, the power is there but damn my mile sucks ( I had a 38 laying around lol, I cant find either of my 2 32/36's)

[mulwyk]

Yes, I've about concluded the big exhaust pipe is the logical next step in my old Toyota's evolution. Maybe next year, after my budget recovers a bit.

My problem is this: when I have more power, I tend to USE IT. If I can just learn to control my right foot, I'm sure my gas mileage will improve.

But Bryan, Wow! You put a 38/38 on a Toyota motorhome? I'll bet that gets your attention when you step on it. Gotta be fun. (And understandable that it might shave a little off the 'ol MPG's)

[90toydolphin]

my dad used to tell me that whatever power i had in my car i would use it. of course i would disagree and say i wouldn't use it, that's what being 16 was all about. we really haven't changed, just the color and amount of hair has. give us power and we will use it, and power comes from the amount of gas we can burn in a short time . if all you want is mpg's then do what fred flintsone did, won't go far but it'll be cheap.

[WME]

Anything you can do to make the engine more efficient will add to your MPG. 2.25" exhaust, header, try playing with the timing, the air cleaner.

OF course anything that makes the engine more efficient makes more power and you know what that will mean

[Totem]

best way to improve MPG is to reduce weight, decrease tire contact on the road (keep them filled at or slightly over), as mentioned reduce restriction, drive heavy down hill and feathery up hill (hyper mile).

You could always install a lexus v8 too; but the jury has yet to report back the actual mpg on such a swap out or report a trips stats. (correct me if I am wrong).

Putting in a after market turbo anyone? (borgwarner etc not the old stock one). I'd be interested in seeing a turbo'd 22re's stats

[Pegasus]

Out of curiosity, why does everyone choose the 32/36? Just for the fuel economy?

I've been thinking of putting a weber carb on my 20r, but I feel like I could use all the power I can get. Would I be better served by the 38, or is the power different marginal? I don't want to turn the humble 20r into a gas guzzler, but if we're talking 1or 2mpg for a noticeable increase in performance.... might be worth it to me.

Edited March 29, 2012 by Pegasus

[Totem]

Out of curiosity, why does everyone choose the 32/36? Just for the fuel economy?

I've been thinking of putting a weber carb on my 20r, but I feel like I could use all the power I can get. Would I be better served by the 38, or is the power different marginal? I don't want to turn the humble 20r into a gas guzzler, but if we're talking 1or 2mpg for a noticeable increase in performance.... might be worth it to me.

I've oft wondered why more people don't consider different axle ratios for the very same reason.

If squeezing more umph out of the motor warrants investment in Carb aftermarket why not match it with a ratio change>?

[WME]

OK a real generic statement. Using the stocker as a base line.

The 32/36 will offer slightly better umph at the same MPG (maybe a bit less)

The 38/38 will offer more mid-range power at less than stock mpg.

Both will be about the same on top end, based on a 2200cc engine.

There to many variables to actually quantify the actual numbers.

IF you are planning on more hopups in the future, cam, header, gears then the 38/38 is a better deal.

WME

Out of curiosity, why does everyone choose the 32/36? Just for the fuel economy?

I've been thinking of putting a weber carb on my 20r, but I feel like I could use all the power I can get. Would I be better served by the 38, or is the power different marginal? I don't want to turn the humble 20r into a gas guzzler, but if we're talking 1or 2mpg for a noticeable increase in performance.... might be worth it to me.

[Pegasus]

OK a real generic statement. Using the stocker as a base line.

The 32/36 will offer slightly better umph at the same MPG (maybe a bit less)

The 38/38 will offer more mid-range power at less than stock mpg.

Both will be about the same on top end, based on a 2200cc engine.

There to many variables to actually quantify the actual numbers.

IF you are planning on more hopups in the future, cam, header, gears then the 38/38 is a better deal.

WME

Cool. Thanks for the reply. I have a performance camshaft waiting to be installed already. Planning to switch to aluminium rockers and a performance header too. Seems like all the easy bolt-ons I can do.

Based on that, I'm sorta leaning towards the 38. Any idea how bad the fuel economy would get? It's still a four-banger afterall... I was also thinking that maybe having the 38 would help avoid having to run a WOT whenever I want to accelerate.

Edit: do the barrels on the 38/38 open at the same time? From what I understand the 32/36 is progressive. Maybe the 38/38 would be worse than I think...

Edited March 29, 2012 by Pegasus

[WME]

The 38/38 is a synchronous design, both open at the same time.

[Dank]

DGV = manual choke

DGEV = electric choke (E = electric);

DGAV = water choke (A = aqua)

DFEV = electric choke (choke linkage rotates clockwise)

Source:- http://www.webercarb...uretors_s/2.htm

Just to chime in with one more related question... Which Weber choke do I want??? I have an 84 22R. Will either of the electric chokes work? I thought the stock carb choke was "automatic, but mechanical in nature (based on temps).

Thanks, Dan

[mulwyk]

Dan:

If you get the Weber conversion kit it will come with a DGEV carb all set up for your 22R engine. The electric choke is plug-and-play for your application....the wire from the old carb plugs directly into the Weber carb choke.

(I think you might be able to get a manual choke version too, but it costs more and would really complicate the installation.)

[MAXXFabrication]

Cool. Thanks for the reply. I have a performance camshaft waiting to be installed already. Planning to switch to aluminium rockers and a performance header too. Seems like all the easy bolt-ons I can do.

Based on that, I'm sorta leaning towards the 38. Any idea how bad the fuel economy would get? It's still a four-banger afterall... I was also thinking that maybe having the 38 would help avoid having to run a WOT whenever I want to accelerate.

Edit: do the barrels on the 38/38 open at the same time? From what I understand the 32/36 is progressive. Maybe the 38/38 would be worse than I think...

your 20r will benefit from the 32/36- or even just a 22r carb adapted, the 32/36 is 1 cfm less than a factory carb on a 22r. your 20r has a 190cfm rating.... and a 32/36 has a 325 cfm and a factory aisin 22r has a 326 cfm obviously.

so just putting a factory aisin 22r carb would be a great improvement.

9 times out of ten people use a weber too get rid of the leaky vacuum lines/clogged/neeeds a rebuildor to get rid of some of the emission B.S. ,

There is an Ca. legal 32/36.

The 32/36 can actually be tuned to run as clean or cleaner than a factory carb even more so when its an old carb in need of rebuild.

My 38 weber is a freakin gas hog in the RV, it was on the yellow truck in the picture below- not really a motorhome type of carb.

I am currently narrowing the yellow truck 12" (thats 30.479999999999997 centimeters to you Derek) and planning on a propane conversion or a 2.7 so I swiped the 38 mm weber off of it after rebuilding the factory aisin with still no idle from it afterward.

[Dank]

Dan:

If you get the Weber conversion kit it will come with a DGEV carb all set up for your 22R engine. The electric choke is plug-and-play for your application....the wire from the old carb plugs directly into the Weber carb choke.

(I think you might be able to get a manual choke version too, but it costs more and would really complicate the installation.)

Thanks Mulwyk,

That's exactly the information that I've been trying to find!

Dan

[Sunrading Arkansas]

Decided this is the next under-the-hood project to tackle. I found this (http://www.yotatech.com/f114/22r-desmog-tutorial-264405/) very helpful...though not looking forward to doling out the $$$. Just have a few quick questions:

1) Mulwyk - did you also install a fuel pressure regulator? Also did you completely remove emissions equip (plugging the Air Injection ports on the exhaust manifold, removing the air pump, EGR, etc.)?

2) Any higher resolution pics of your engin bay?

I found out yesterday that my A/C compressor is shot (loud rattle when engaged at above idle rpm), so looks like I'll be ditching that as well....It'll be pretty nice to run so simple - easier diagnostics, easier to fix.

And as always, Thanks for the info/help!

[Sunrading Arkansas]

Well, I ordered everything in the Yotatech how-to for a De-smog and Webber 32/36 DGEV conversion (including the LCE spiral adapter), so I'll find out soon enough. Hopefully by next weekend...I'll report back with my results.

[MontanaChinook]

I'll be paying attention. Seen the threads on yotatech for years but haven't done it myself. It'll probably happen for me sometime this year.

[Sunrading Arkansas]

Sooo, finally got this project done....it turned into De-Smog, Weber Carb, new Brake Master Cylinder, Valve Adjustment, new Valve Cover Gasket, new Radiator Hoses, new Radiator, and new Thermostat, and a new Water Pump (just for fun). The result of the De-smog and Weber upgrade seems GREAT! Noticeably more pep, less down-shifting up hills, and a WHOLE LOT cleaner engine bay. I basically followed the install directions from here (http://www.yotatech.com/f114/22r-desmog-tutorial-264405/).

Before:

After:

Literally a Wheel Barrow full of parts removed from the Engine Bay:

The Weber 32/36 DGEV:

The New Water Pump and the only 2 remaining vacuum lines:

This was my only deviation from the YotaTech Tutorial, as my Air Injection Ports were directly on the exhaust manifold. So they were tapped with a 7/16 and bolted up:

I'll be selling all of the complete set of WORKING emmissions equipment, original vacuum lines, and carb (with only 35k miles on all equipment) as soon as we return from our summer trip (so the beginning of August). If anyone decides to do as I've done and has any questions just let me know.

[MontanaChinook]

Nice work! Why did you remove the exhaust manifold heat shield?

[Sunrading Arkansas]

I removed it because it was ported into the factory air intake (i assume to preheat the in-draft air) and looked kind of goofy without that attached...if there is an excessive amount of heat build up in the engine bay, I'll modify it by cutting the "snorkel" off and reinstall it. I guess I'm erring on the side of less is more until proven otherwise.

[MontanaChinook]

Sounds good to me.

Once I can stop spending money on just getting my Chinook functional again, this conversion is high on my list.

[Sunrading Arkansas]

Just a couple tips - I ended up not using the Crossover block-off plate from LCE - as it seemed redundant (but I have it, so I may throw it on there at some point). Also, I ordered the Weber from Webercarbsdirect's Ebay store as it was 2/3 the cost of one through LCE (I used the saved funds to get LCE's spiral adapter kit, which seals better and supposedly increases HP a little). I think all-in it cost around $500 for the conversion/desmog specific parts and probably about 10 beer-hours of work. And from what I've read, one should be able to recover most of the cost from selling the emissions and stock carb...if one decides to do that.

[MontanaChinook]

Thanks. Yeah I'm definitely not buying the carb through LCE.

I appreciate the cost info. These things always cost more than I plan on, so it's nice having a realistic figure.

[86rader]

I would love to find a 22R 4/5 speed shorty Sunrader. I am confident that such a rig could be hypermiled into the 20+ mileage club. What I would really like is such a rig with the 22RE. The Weber works great but FI gives you the ability to shut fuel off while engine braking which helps a good bit when hypermiling. Also if you are out west where you may experience large elevation changes, the RE takes care of fuel ratio changes all by itself.

This leads to the question of doing a 22R>22RE swap. How difficult is this? Can all the FI stuff be bolted up to a 22R? Or do you need to just swap the entire engine? Are there wiring nightmares involved with installing an RE into an older R truck?

And one last question? Is there any way to have DFCO (decelleration fuel cut off) with a weber? It really would be handy for long downhill stretches.

[Sunrading Arkansas]

@86rader - The 5 speed would definately be a good upgrade - one I might consider doing in the future (the guy I bought my full-float axle off of has a Mirage with a 5 speed and he said he was averaging 25mpg [up from 20 with a 4spd] - of course those are a ton lighter than a Sunrader). I was getting 17.6mpg with the stock carb/emissions set-up, and anticipate about the same with the Weber. The primary reason I went Carbed - and Weber specifically - was ease of maintenance. They are easy to adjust, diagnose, and rebuild. EFI is a whole other monster and it's getting harder/costlier to maintain those older set-ups. Can a conversion be done? Absolutely, at least on 83 and newer 22r engines - easier on 85+ (see yotatech and LCE for info, parts, kits, etc). Would I do it? No. I like the peace of mind of at least understanding and for the most part being able to repair my own vehicle - with EFI, I can't do that - esp. on the road. But, If I wanted EFI real bad I'd probably do a complete engine/harnes/dash/etc. swap from the lowest milage vehicle I could find. No DFCO on a Weber.

Just my $0.02