TheSamba.com :: View topic - Carburetor 34 PICT-3 Accelerator Pump Problem

Thu Jul 10, 2014 11:24 am

I've got a 34 PICT-3 carb that stalls as soon as I pump the pedal. I've rebuilt and cleaned the carburetor 3 times now and still the problem persists. I can tell that there is no fuel coming out of the u-shaped nozzle (name?), but I can't seem to figure out why. I've run compressed air through every jet and hole I can find, but still no luck.

I'm hoping someone out there has had a similar problem and can help me out. I've searched all over and found a some good advice, but I'm still stuck. Thanks.

Thu Jul 10, 2014 11:48 am

Since you've re-done the carb three times, it's past time to just send the thing off to Tim at Volkzbitz. He's the master, and he doesn't gouge you. And it takes about a week, but you get back a carb that's like new.

Tim

Thu Jul 10, 2014 11:54 am

Ok first make sure there's fuel in the carb bowl. The when you move the arm if nothing comes out the U tube, take the diaphragm off on the right side of the carb. Is it torn? Does it show fuel on the side facing the carb. Maybe you didn't include the spring.
Another to check is if the free flowing ball is there inside the pump body. When you shake the carb you should hear it.

Thu Jul 10, 2014 12:32 pm

Yes, there is fuel in the bowl and I did replace the diaphragm and spring is in place. I don't hear a rattle. Could it be missing or stuck?

I've considered having it rebuilt, but it's a Bocar carb not German. Is it worth it? Or should I just buy one of Tim's rebuilt german's?

I've also considered going with a dual weber 34 ICT kit. Opinions?

Thu Jul 10, 2014 12:52 pm

when you cleaned it, did you take the plug in the main bowl off and clean? if not there could be gunk still in that passage and the ball is stuck or missing.
Don't waste your money on aftermarket carbs. they are not german and has various issues. Stick with Tim's

Thu Jul 10, 2014 1:23 pm

There are two check balls:

The inlet one in the bowl - you'll need a long M4 screw to which you can clamp a wrench to and tap on that to pop the retainer plug out:

The outlet side is here: (this is an H30/31PICT example but it's the same place on the 34PICT-3: You have to remove the dump tube/jet to get this ball out.

Have you verified flow through the dump tube/jet?

Also, if you get it working and want to change the adjustment, ignore the plus and minus marks on the adjustable linkage. Adjust it until all of the play/slack in the linkage parts is taken up.

-Andy

Thu Jul 10, 2014 1:29 pm

Thanks, Andy. Very helpful stuff.

I'm guessing that one or both of these are clogged with gunk. I'll clean them both with your instructions.

Sat Jul 12, 2014 1:11 pm

Following Andy's instructions, I removed both check balls and did another soak in carb cleaner then a thorough blow through with compressed air. Carb is working like new again.

Thanks again for the help, guys. Except for Tim the pessimist. Hope you're at least getting a referral fee! :lol:

Sat Jul 12, 2014 4:13 pm

How was I to know glutamodo was going to get into this thread and, not only teach you, but have you actually do the work, yourself? You said you rebuilt the carburetor three times. It seemed to me that it was time for someone else to give it a go. I know (actually, everyone here knows) that Tim is your best bet for carb issues.

I don't get any referral fees. Not that I would take any money for referring any AVCW owner to people I know will do right by them.

I'm glad you were successful in solving the problem :wink:

Tim

Sat Jul 12, 2014 5:10 pm

Tim,

I meant my comment to be humorous, but I can see how you took offense. My sincere apologies.

And thanks for pointing me Tim's way. Someday my bushings will wear out and I'll be sure to give him a call.

Aaron

Sat Jul 12, 2014 7:06 pm

Now I'm going to have to call up Madame Hood-doo in New Orleans and have her lift the curse .... 8)

Tim

Tue Jul 15, 2014 4:06 am

same thing happened to me, i forgot that check ball for the accelerator pump. the trick is to use a tail light screw to remove that plug. Those germans...

Fri Aug 31, 2018 5:50 am

Awesome write up. The same thing was happening to my Solex 34PIC3 carb after I rebuilt it. When I followed this procedure and shot carb cleaner down the passages, I lot of gunk came out. Now I have excellent throttle response; very happy.

Sat Jan 22, 2022 4:01 pm

So what holds that pin in place?

glutamodo wrote: There are two check balls:

The inlet one in the bowl - you'll need a long M4 screw to which you can clamp a wrench to and tap on that to pop the retainer plug out:

The outlet side is here: (this is an H30/31PICT example but it's the same place on the 34PICT-3: You have to remove the dump tube/jet to get this ball out.

Have you verified flow through the dump tube/jet?

Also, if you get it working and want to change the adjustment, ignore the plus and minus marks on the adjustable linkage. Adjust it until all of the play/slack in the linkage parts is taken up.

-Andy

Sat Jan 22, 2022 4:29 pm

The pin is slightly larger than the hole it goes into. So it is held in by simple friction.

Sat Jan 22, 2022 4:29 pm

Friction holds the pin in place.

Once you get the little accel pump circuit and check balls working and nozzle spraying in the right direction, I'd recommend a little penetrating loctite green to keep the nozzle from falling into the engine.

Sat Jan 22, 2022 4:52 pm

This won't hurt http://1967beetle.com/carburetor-rebuild/

Sat Jan 22, 2022 6:35 pm

Thank you. I missed this on my carb clean and I'm having issues when I hit the acclerator suddenly versus gradually. I suspect that may be the issue.

Sat Feb 10, 2024 10:57 pm

I realize this is an old thread, but I had a plug that was not threaded and I could not get an awl that was small enough to fit through the hole yet thick enough to apply enough upward force on the plug to remove it (skinny awl fit through the hole, but would bend before moving the plug).
What I did was get a screw extractor kit and used the smallest extractor and threaded it into the brass plug a few turns with a pair of pliers. Then I clamped vise-grips onto the extractor and worked the plug out.

This 34 PICT-3 appears to be the stock carb in a 71 bus.

Cheers

Thu Jan 16, 2025 12:13 am

:thumbsup: