weber 32/36 conversion woes

[jamesh]

Hi All,

 

I am driving a 1985 720 4wd 2.4 l engine.

 

When I bought the truck, someone had swapped out the factory carburetor for a 32/36 dgav electric choke style carburetor.  I recently took it off of the truck and have been cleaning it.  It is unassembled and I am waiting on the rebuild kit.

 

Some things I've noticed that I could use some help on.

 

Before I removed the carburetor I was having trouble starting it, it was the first really warm day we'd had, and I still had the choke spring adjusted for colder weather starts.  When I finally got it to turn over it sounded horrible and I cut it off and noticed a bunch of fuel leaking all over the place.  This was my moment of inspiration for removing the carburetor.  There is a single fuel line going to the inlet on the carb, without a pressure regulator, and the return line is T'd off of this line.  Something tells me this isn't correct, but I don't know, it had been running fine for years like this.  The fuel pump constantly runs when I have the key in the "ON" position.  I assume this is because fuel is being delivered and returning once pressure has cut off fuel to the float chamber, and then the pump just kicks it back to the tank..

 

I had thought about installing a fuel regulator, probably a bypass type so that I can plug the return line into it.  I was also going to get a fuel cut off solenoid while I am at it, as the truck had some rough dieseling issues when I was switching the key to off.

 

Is there any information out there on original fuel line routing and how the fuel should be returning to the tank.

 

Where should I jump power from to give to the idle cut off solenoid>?

 

Thanks for any thoughts about this!

 

James

[jamesh]

One additional thing.

 

Is there any info on the type of main and secondary jet sizes that should be used for this truck with this carburetor (or does anyone have a successful set up they are using?)

 

For the factory, the book was telling me 94 on main and 170 on secondary.  As it stands now, the weber has a 160 main and a 170 secondary.

[datzenmike]

Yeah, Webers are much different than the factory jets so don't go by that.

 

The return line is only there so that cooler gas is constantly passing the carburetor. These engines run hot and under hood temperatures can spike after shut down and boil the gas in the lines and carburetor making a restart difficult. The return line has a restriction in it so that the pump can build some pressure, or it would all just run back into the tank. Can you post a picture of how it is set up? Maybe the return line is OK. The stock fuel line is just a Y with a line from the pump, one into the carburetor and one for the return. You won't need a regulator as the pump is regulated at about 3-3.5 PSI. It runs all the time but when the carburetor is filled it slows down.

 

 

The flooding is probably just the float stuck. A rebuild should fix this and maybe the float height setting was wrong too.

 

Idle cut is a great idea. You can connect the idle cut to the choke heater wire. (usually the choke heater is a Blue wire and the idle cut is Red, they may have a Black sheath on them) Both turn on and off with the ignition.

[jamesh]

Thanks for the reply.

 

What you are saying makes sense.  I figure before I spend any more money, I will just see how it runs with a clean-up/rebuild.

 

Its pouring down rain here, but I'll take a picture and post it tomorrow.  In my memory, I think it is a "Y" and not a "T".  But it is like you said, fuel pressure line up and into a "Y" - one arm to the carburetor and the other back down toward the tank.  Would the restriction in the return line be something "in-line" with the return hose (hose clamped and noticeable?) or would it be part of the "Y"?

 

One more thing that I wanted to mention and had forgot; when I was attempting to get the idle adjusted on this truck, I had to back out the screw significantly more than what the factory recommended.  If I remember right, I got it to run smooth around 3+ turns out.  I think I remember reading something about adjusting jet sizes if you have to mess with the idle adjust screw that much.

 

As for the idle-cut, that was my first guess as far as where to get the power from.  Thanks.

[datzenmike]

I think it will be in the metal T.

 

This is for an L20B and the small hole is at the end of the line where the hose connects down to the return line on the frame...

 

 

Like I said the hole can't be too larger or the gas will go past the carb and right back to the tank.

[Charlie69]

First do not bypass the factory Y pipe with the return line in it.  Second does your Weber say made in Spain on it.  If it does not have made in Spain on it then it is a Chinese knock off.

 

If it has ran fine for years why would you mess with the jetting?

 

Be sure to check for vacuum leaks when you put the Weber back on.

[jamesh]

2 hours ago, Charlie69 said:

First do not bypass the factory Y pipe with the return line in it.  Second does your Weber say made in Spain on it.  If it does not have made in Spain on it then it is a Chinese knock off.

 

If it has ran fine for years why would you mess with the jetting?

 

Be sure to check for vacuum leaks when you put the Weber back on.

 

There is a small tag that is attached to one of the bolts. It has some

numbers and says Made In Italy on it. Would there be a stamp on the carburetor itself?

[AlexDeLarge]

Yes, it has a large W and Made in Spain stamped into the carb body.

Edited May 23, 2020 by AlexDeLarge
added photo

[Charlie69]

If you truly have an Italian made Weber it is at least 15 to 20 years old.  The new Spain made Webers do not have the little metal tags on them   Make sure the throttle shafts are not worn as this is a possible vacuum leak.  I do not have any Italian made Weber's any more that I know of.  A friend of mine has all my used Weber parts.  Pictures are of a new Weber I have for the rebuilt Z20 I plan on installing in my 86 720 2WD King Cab.

 

 

 

 

 

Weber Prodution moved from Bologna, Italy to Madrid Spain in 1992.

Edited May 23, 2020 by Charlie69

[jamesh]

OK, so I can't figure out to upload images without having al URL?  Is this the only way or is there a drag/drop or upload from computer/phone function?

 

I am trying to add a shareable link to a google drive folder - any help with adding photos inline, without a URL would be appreciated.

https://drive.google.com/open?id=1Mb3xTVikHH_FMlW4EWqlQ6YT_HNUBvCV

 

There is a stamp that says made in Italy on the body of the carburetor, where the choke body mounts to the lower portion.  If you can view the other photos, I'd be interested to hear any other comments.  One of the photos shows the fuel line routing, and exactly where the "T" is located.  I do plan on re-doing the fuel lines when I reinstall the carburetor--still waiting for the rebuild kit.  Another thing I noticed is on the rear, right bolt coming from the intake manifold.  It looks like whoever did this work did a relatively subpar job of mounting the carburetor, I am going to look into this, and re-doing it, but any experience-based tips with respect to this would be helpful.  There is also a picture of the vacuum line routing, and I am not entirely sure where the one line that mounts to the carburetor goes to-it looks like it heads toward the crankcase.  So maybe a PCV?  Anyway interested to hear what you all think, and hopefully you can view the files.  If not let me know and I'll try something else.

[Madkaw]

You have to use a host site to post pics . 
Webers usually give people issues with air leaks because of the adapter plates . 
If share my jetting , but no sure if it correlates to your carb . I found the stock jetting for the 32/36 to be lean in most areas . The only way to counter that is to have the mixture screw out 2 turns or max which means a pig rich idle .

Get a wide band and tune with it . I bought a redline jetting kit and used the biggest jets it had on a fresh motor . My mixture is only adjusted out about 1-1/8 turn 

[datzenmike]

As mentioned elsewhere the adapter plate can crack from over tightening. This is usually because the bolts/studs/nuts come loose and can cause vacuum leaks so people tend to re-tighten them and over do it. Use a thread locker on the bolts and studs and do it right the first time.

[jamesh]

The adapter plate looked OK, it was the manifold itself, where it looked like someone tried to cut off one of the studs and then retap it for a smaller bolt. Anyway, it just looks like a small hairline that doesn’t go the whole way through.

 

Normally my automotive projects turn into more than I bargain for.

[jamesh]

Was anyone able to use the above link for the google document images?

[jamesh]

Hi all.

 

Everything made it back onto the truck with no extra pieces. I pulled almost all of the vacuum lines, as several were routed incorrectly anyway.

 

I have 2 observations and would appreciate any insight and opinions.

 

The truck fired up immediately and idled with hesitation for a moment before cutting out. I started to adjust mixture for lean-best, and, as was the case before, I had to back the screw out about 2 1/2 turns. It does seem to idle just fine, maybe at a slightly higher RPM than before. I almost have no adjustment on the idle speed screw, which is also a little bit different than previously.

 

The other observation is that it diesels pretty badly when I cut off the engine. Typically it would do this maybe one in twenty times (one in five times on its worst days). I do have an idle cut off solenoid coming in the mail and was going to play with that, but I can’t help wonder if these two items are related.

 

I also found an old post

 

And this actually lists some specs for the 32/36, which are pretty close to what I have in there, but not exactly. Both of my idle jets are 50, and the specs listed above call for 55 on primary/50 secondary. How much difference would that make?

 

Anyway thanks for any responses and thoughts.

[Charlie69]

Yes I was able to view your pictures.

 

Here is a Weber baseline jetting chart.

 

Z24 1 piece adapter.

Edited June 1, 2020 by Charlie69

[jamesh]

That is really helpful, thank you. It’s interesting because according to the literature I have referenced, Weber recommends increasing primary idle jet when the mixture has to be turned out >+2 turns, which is where I am at.

 

all of my jets are as listed for the 32/36 dgav except the idle, and as of now the primary idle is undersized.

 

Will report back on this once I play with it, idle cut off solenoid comes on Friday!

[datzenmike]

Make sure there are no vacuum leaks. More air getting in will need more fuel and turning the idle out.

[Madkaw]

What he said ^^^^^^

[jamesh]

Spray starter fluid around the carb w truck running and listen to engine?

[jamesh]

There aren’t many vacuum lines to be leaking, and I capped off anything that did have a line previously.

[bottomwatcher]

You have any idea of the miles on the carb? I ran one for 20 plus years and probably 150k. The standard rebuild kit doesn't solve the shaft and bore wear issues. The idle was crap until I replaced the shaft bushings with sealed ball bearings. Best improvement to the carb I ever made.

[Charlie69]

Main places to test for vacuume leaks are the carb base and the adapters.  I use what ever I have on hand for testing for vacuume leaks,  WD40, carb cleaner, brake clean, and already mentioned starting fluids.  I like the tiny hoses so I can pin point where the leak is.  when you hit a vacuume leak with one of the afore mentioned products the engine will gain rpms so turn of the radios and listen to your engine.

[Madkaw]

21 hours ago, jamesh said:

That is really helpful, thank you. It’s interesting because according to the literature I have referenced, Weber recommends increasing primary idle jet when the mixture has to be turned out >+2 turns, which is where I am at.

 

all of my jets are as listed for the 32/36 dgav except the idle, and as of now the primary idle is undersized.

 

Will report back on this once I play with it, idle cut off solenoid comes on Friday!

If you can get the mixture screw down to less than 2 turns you might not need cut off solenoid. I’m running 1-1/8 out , but have netted up other things and no vacuum leaks . Adapter plate is the biggest issue

[jamesh]

I like the idea of putting bearings in, but I’d like to address the simplest things first, and fine tune from this point. For e.g. the throttle return spring has been rigged to the supplement hydraulic clutch booster line... the throttle cable bracket had never been lined up very well and so that hasn’t helped things either. This is another project. I made a new bracket but have since ordered an adapter through redline.

 

As for the adapter plate:

when I reinstalled, I cleaned up the questionable work. When I removed the carburetor, one of the studs hadn’t been seated into the intake manifold, it had been, amazingly, tapped into one of the frozen manifold studs. Anyway, I removed all of this and started over. When I reinstalled the intake manifold to adapter plate gasket, I put a thin coat of grease on the intake manifold side. (This was recommended by redline).

 

How do you all check for leaks? Vacuum or otherwise.