32 ADFA carb problem

[Turbofiat124]

This is the carb used on 1800 models. First of all apologies for this being about my 131 Brava but this 1800 intake and carb came from an 1800 Spider so maybe that will count.

I pulled the original 1979/1980 28/32 ADHA (correct?) and intake off and installed the 1800 setup which is supposed to be the bomb but so far it hasn't proven to be any better than the 79/80 setup.

I rebuilt this carb and have had success in the past rebuilding 32/32 DFTA Webers used on Yugos but this one is giving me issues.

First issue:

By the way this car is an automatic.

I have to ease into the throttle from a dead stop otherwise the engine will stall. I believe the stalling occurs if the secondary opens at too low RPMs so I need to make sure the car is going at least 30 mph before I open the secondary.

Now whether this is a result of too much fuel or too much air I don't know. At highway speeds when I open the secondary this is also noticeable as a half second “blip” but does not really affect anything.

I do know the accelerator pump is working. I can rev the engine up at idle and it sounds great and I can see fuel being squirted into the venturi.

I was hoping the secondary jet may be clogged (wishful thinking) causing a very lean mixture when the secondary opens but after soaking, picking the holes in the jet and emulsion tubes, etc. this has no effect.

But the accelerator pump is leaking externally. I can't remember if the rebuilt kit came with a new accelerator pump gasket and diaphragm or not but it should have. I don't know why else it would be leaking.

If you can trust Fiat gauges (which I don't) the car has used about 6 gallons of fuel over the course of 70 miles. I estimated anywhere from 11 to 14 mpg. That cannot be good.

Idle speed is around 1200 rpms with the idle speed screw backed all the way out.

Engine starts up fine but does not idle fast like it should. Same speed as if it is at normal operating temperature. The fast idle mechanism seems to be OK.

I haven't messed with the jetting. It still has the original jets. However these is a possibility they got accidently reversed when I rebuilt the carb. Any chance that would cause these issues?

Any clues as to what is wrong with this carb?

[digitech]

Yes, mixing up the jets can cause your issues but it can also be misadjusted secondary, misadjusted float level, air leaks in and around the carb/intake and more. But, first things first - solve the leaking accel pump first.

[vandor]

>have to ease into the throttle from a dead stop otherwise the engine will stall.

Means the accelerator pump is not or barely working. Probably because it is leaking externally.

Every rebuild kit that I've seen comes with the accelerator pump diaphragm, but they are also available separately.

> I believe the stalling occurs if the secondary opens at too low RPMs

The secondary only opens when you go past ~70% throttle, so I doubt you are getting into them.

[So Cal Mark]

your accelerator pump cover may be warped, causing the leak.
If it won't idle down to the point it stalls, the secondary may be staying open slightly. There is an adjustment screw to set that opening.
If you've mixed up all of the jets, it's probably time to start over. Generally with a carb, if you don't know what is causing your problems you won't be able to fix it without blind luck.

[Turbofiat124]

Yes, mixing up the jets can cause your issues but it can also be misadjusted secondary, misadjusted float level, air leaks in and around the carb/intake and more. But, first things first - solve the leaking accel pump first.

Unlike the DFTA and DMTR carbs which I have had more experience with, the air corrector and jet are pressed onto the emulusion tube which screws into the float bowl and comes out as a whole deal, I was a bit confused (or forgot) how to remove the mains from an ADFA.

On this carb the air corrector unscrews from the emulusion tube leaving it stuck in the float bowl. I evenutally figured out it's more less pressed it. So I inserted a small screwdriver and wiggled it around until it came out.

It looks like the emulsion tube and jet are one piece. Is that correct? If not is the jet pressed onto emulsion tube or screwed on?

What would be the numbers to I can determine if I have the jets mixed up?

[Turbofiat124]

>have to ease into the throttle from a dead stop otherwise the engine will stall.

Means the accelerator pump is not or barely working. Probably because it is leaking externally.

Every rebuild kit that I've seen comes with the accelerator pump diaphragm, but they are also available separately.

> I believe the stalling occurs if the secondary opens at too low RPMs

The secondary only opens when you go past ~70% throttle, so I doubt you are getting into them.

It's been awhile since I rebuilt this carb but seems to me I recall a part that should ordinarily come with a new kit was missing and I think it was the accelerator pump diaphram which I recylced.

I have several of these carbs (mostly just for parts because they are missing parts) so I can rob another accelerator pump and diaphram and see what happens.

One more thing. I *think* I have the hose that goes to the vacuum canister connected to the intake manifold. Otherwise the controls either don't work or the heater valve closes at idle. I fixed that with a ball valve and plugged off the hose going to it.

This leads me to believe either the canister is busted or the check valve in it is leaking. Adding an external check valve may fix that.

That system is messed up anyway. The electronics work (like the A/C) The only "flap" that seems to work properly is the one that recircs the air when the A/C MAX button is pressed. Defroster valve is always open.

If that is the case, then perhaps that is a source for a vacuum leak.

[FordPrefect]

If it's ok to ask in this thread:

I'm working on my 32adfa right now, and the secondary emulsion tube is stuck in the carb. I rattled the other one out ok, but this one doesn't respond to even light tapping on the backside with a screwdriver handle. Any ideas?

[124JOE]

blow it out with compressed air thru the hole in the bowl
or try to get it to turn

[FordPrefect]

Found a book on Weber carbs, and it actually recommends using a tap to make 3-4 threads in the tube and then pulling on the tap.

The compressed air idea isn't bad either, but haven't got a compressor that would be up to the job.

[Turbofiat124]

There is an adjustment screw to set that opening.
If you've mixed up all of the jets, it's probably time to start over. Generally with a carb, if you don't know what is causing your problems you won't be able to fix it without blind luck.

Mark do you care to point out which screw your referring to on this exploded diagram that is used to adjust the secondary?

http://www.piercemanifolds.com/v/vspfil ... d_ADFA.gif

[manoa matt]

Its a tiny set screw on the secondary throttle shaft. #41

To get the emulsion tubes out get a paper clip and bend a 90 deg angle so it can be inserted down the center hole and engage one of the emulsion tube holes, then you can yank it out. Or get a tapered pick and insert it into the center hole and wobble it around until the emulsion tube loosens. I would not try to thread it, brass shavings will get clogged in the fuel passages.

Turbo, send me an email. There is much more to rebuilding a 32ADFA that is not covered in the factory manual. Fiat put out a 32ADFA workbook that is a supplement to the factory manual and covers ALL the adjustments and specifications.

matt.scarton@gmail.com

[Turbofiat124]

Its a tiny set screw on the secondary throttle shaft. #41

To get the emulsion tubes out get a paper clip and bend a 90 deg angle so it can be inserted down the center hole and engage one of the emulsion tube holes, then you can yank it out. Or get a tapered pick and insert it into the center hole and wobble it around until the emulsion tube loosens. I would not try to thread it, brass shavings will get clogged in the fuel passages.

Turbo, send me an email. There is much more to rebuilding a 32ADFA that is not covered in the factory manual. Fiat put out a 32ADFA workbook that is a supplement to the factory manual and covers ALL the adjustments and specifications.

matt.scarton@gmail.com

Found out what was wrong with my carb. I think. First of all the accelerator pump was leaking externally. I knew that but that may have contributed to my problem. I must have got ripped on my rebuilt kit because I think I had to recycle this part. I believe it had a pin hole leak in the diaphram. So I pulled one from a junk carb and fixed it.

Second I found rusty funk in the bottom of the fuel bowl that is getting past the filter. I'm thinking the secondary jet was clogged. I cleaned both jets out.

The car runs like a top now! Allot more power and no hesitation from dead stops.

So I guess I fixed the problem until the jets clogged up again. Hopefully I can find a better fuel filter.

[124JOE]

Hopefully I can find a better fuel filter.

or two