Idles. Stumbles and dies. Things are getting worse. HELP

[denver_74]

H block. 34 Pict 3 Carb. Stock vacuum advance distributor.

Starting a new thread - its a continuation of "is it vapor lock?"

Long story short after the car was warm, it would die after hard acceleration. High RPM let off the gas, put in the clutch and it would just quietly die. It would start up and idle and i could drive it if i kept the revs low and drove it lightly


Things I have done and the result.

Installed new points and condenser. 44º dwell. 914 RPM idle. The problem did not improve.

Turned the idle mixture screw in one half turn and it ran worse. Stumbled, misfire,back fire.

Turned the idle mixture back to it original position and it stumbled etc less but it was still bad.worse than just dying at stop lights.

Popped the top of the car and there was rust sediment at the bottom of the bowl. Cleaned it out sprayed carb cleaner. Installed a new gasket. And now the car barely idles. Hit the gas and it goes flat if it does pick up it lags and dies.

Getting frustrated because things seem to be getting worse.

I ordered another set of points and condenser thinking the ones i picked up at the local advance auto might not be correct.

The car has run trouble free for 6 years but when i pulled it out of storage this year i didn't have time to put the drive time into it that normally would. Now I can't even get it out of the driveway without it dying.

Don't know what I should or shouldn't be doing. Sort of opened up the issue on two fronts: ignition and fuel/carb. Feel like i am making things worse and i don't know what the issue might be.

Getting ticked

D74
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1974 Standard Beetle Sunbug

[joey1320]

If I was in your shoes I would remove/disassemble the carb and give a thorough cleaning.

Did you try backing off the idle mix screw half a turn past its original setting?
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[denver_74]

i went a quarter turn back with the engine running and didn't notice a change.

i am wondering if i didn't clog the main jet t=during my cleaning attempt
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1974 Standard Beetle Sunbug

[busman78]

Pull the idle jet look for a spec of dirt blocking it. When you look down the barrel and pull the throttle do you get a steady squirt of gas, if not then the pump jet is plugged or passage. Remove it and clean it by blowing cleaner from the nozzle back through the tube. Not sure if that will cure your problem but it won't hurt.

[wcfvw69]

X2 on pulling the carb completely apart. Soak it in Berrymans carb cleaner for a couple of hours. Then, put both parts and all the jets (removed from the body) in an ultrasonic parts cleaner. Harbour Freight sells the for $70 dollars and they work REALLY good.

Your symptoms sound like a dirty idle circuit or jets. When you put the carb back together, make sure you measure the fuel level in the bowl. It's VERY important this height is correct for the idle circuit.
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[sb001]

IMO you simply have a bad vacuum leak probably at the throttle bushings in the carb. At any rate I can almost guarantee that the carb IS the root of your problem. It MUST be sent to Tim @ volkzbitz. You will never get it to run properly unless it is professionally restored. I must do the same with the 34 PICT 3 on my 72 super.

[denver_74]

fortunately the carb is 6 years old

BUT yeah... i guess it needs to come off.
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1974 Standard Beetle Sunbug

[wcfvw69]

[Mikedrevguy]

Is the idle solenoid cutoff snug?
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74 1303 (RevBug): plan for German Look
76 914 with 2260
79 VW Iltis
69 Bwajaja
"The wise speak because they have something to say; while the foolish speak because they have to say something." Plato

Illigitimi non-Carborundum!!

[denver_74]

if memory serves it is a Bocar carb.

i haven't had an issue with it since it went into service 6 years ago. obviously rust particles in the bowl are going to screw things up. i have always run a filter so in addition to cleaning out the carb - i need to find the source of the rust. not sure how good those plastic filters are but i was surprised at the amount of rust in the bowl.

idle solenoid cutoff snug and clicking.
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1974 Standard Beetle Sunbug

[joey1320]

Can you ask the mods to delete the other thread?

If you don't use the car on e regular basis and it gets stored on the winters, rust will form. It's just a byproduct of the fuel just sitting in a metal tank. Just remove the carb and give it a thorough cleaning and go from there.


Link

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**1971 Super Project
https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0

[VW_Jimbo]

You can check for a vacuum leak with a can of aerosol carb cleaner. I always start at the intake to head gasket areas. Just aim the straw at that area and spray a tiny shot at that gasket. If the Rpms increase in response, you most likely have a vacuum leak where you sprayed. You can then test at the base of the carb and throttle shaft bushings. When spraying near the carb, be aware that those loose combustible molecules will find there way into the carb intake, so do not get mislead by that. You need to be methodical and aware of the response. Vacuum leaks are immediate. When those loose molecules find their way into the carb throat, there is a slight lag in rpm response. It's all by ear. Takes a little practice but lends itself to accurate diagnosis once proficiency is achieved. Small learning curve, but not hard. For starters, you can spray a quick shot directly at the carb intake. You will either get an increase in rpms (lean) or a bog (rich). You want a very tiny bog. Diagnosed 1000s of carb with this method, from Datsun side drafts, 4 barrel GMs, 8 barreled ferrais, to the single solex on a bug. It works every time with solid results. Propane torches (unlit) work well too. Those lighting clicker things my wife uses for candles will also work (I was in a pinch and grabbed one, just disable the piezo from igniting!) Although the flame does lean towards the vacuum leak area when it gets close, but the result is not good! Been there.
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Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

[denver_74]

rust: i get that rust form from age and storage. i was just curious how its making past the filter...unless those plastic filters are as junky as they look. i would think i would see deposits on or in the filter.

vacuum leak: i started to do a spray down and ran out of carb cleaner lol. nothing changed as result but again i didn't do a complete test. just the manifolds.

both the engine and the carb have very low miles. the carb was new when the rebuilt engine was installed 6 years ago.

my dad was diagnosed with stomach caner and it sat for a summer before he passed away. my uncle who is a skilled vw bug enthusiast got it running and tuned (i do not know if he drained the tank - if recall the answer is "yes") i haven't touched the carb since only to drain the bowl for storage. (i also store the car with a fuel tank and K100),

after work tonight i am going to have a little time so i will see if anything has changed over night. after that i going to check the bowl, inspect/clean the main jet and idle jet. and see if conditions improve.

after that vacuum spray test.

and from there start drinking??

(the filter set up has changed from the photo below))

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1974 Standard Beetle Sunbug

[sjbartnik]

[denver_74]

rebuild parts on order.

did the vacuum spray test. no changes

cleaned out the bowl (yet again).

measured fuel level in the bowl: 22mm (only one thin steel washer
float valve washer under the float valve)

cleaned pilot jet, main jet, air correction jet etc etc. and all openings with chem tool, blasted everything with compressed air.

and while its not perfect the car is no longer stumbling or dying when i hit the accelerator. (an improvement over yesterday)

i was unable to road test (ran out of time) but i did some sustained high rev pulls on the throttle in the driveway and 3 out of the 5 times it didn't die.

so problem not solved but better
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1974 Standard Beetle Sunbug

[sb001]

[wcfvw69]

Here's what your float level should be.

This picture shows the fuel level in the carb and it's importance in the idling circuit.
_________________
Contact me at [email protected]
Follow me on instagram @sparxwerksllc

Decades of VW and VW parts restoration experience.
The Samba member since 2004.

**Now rebuilding throttle bodies for VW's and Porsche's**
**Restored German Bosch distributors for sale or I can restore yours**
**Restored German Pierburg fuel pumps for sale or I can restore yours**
**Restored Porsche fuel pumps or I can restore yours**
**Restored Porsche distributors or I can restore yours**

[VolkzBitz]

[denver_74]

float level: if i understand correctly, my float level is low. i measured from bowl rim to fuel using a right angle gauge with the car on level ground. if i have one thin washer how do i raise the float level? remove the single float washer??

EGR connection: this is interesting. i will cap the current port on the carb.
move the redline to the 45º port? if i don't have 45º port? does the red tube get capped as well or leave it open?

d74
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1974 Standard Beetle Sunbug

[wcfvw69]