Problem trying to get my 74 to run correctly.

[GBodyVillain]

Hey guys, new here. I've had a 74 beetle for some time and never drove it because it just don't seem to run right. I've done some basic things to it to try to get it to run a bit better. The main issue I'm having is it runs and idles sort of okay, then after a little bit if I try to hit the throttle it just sputters and dies. I admit I don't have a ton of experience with these cars.

So one of the things I've done so far was rebuilding the 34PICT-3 carburetor. While rebuilding the carb I noticed the previous owner just put some sort of plug where the idle air jet goes. I took it out and replaced it with an actual idle air jet but it would maybe catch just the start of the thread and would not advance anymore. I looked into the hole and noticed the bore was nowhere near what it needed to be for the idle air jet to fit. Of all the available pictures I could find of this carb, all of them show the idle air jet seated fully into its place. There was a large shoulder inside the hole and I enlarged the bore so the idle jet could fit and got it with as little wiggle room between the jet and the hole as possible and got it as deep as I figured I could then cleaned it out and finished the rebuild. I'm waiting on another carb because I know for a fact I don't know what I was doing with my little modification and want another in case I messed this one up. However, upon installing and running the carburetor I didn't find any issues and the car seemed to run no differently. The bypass and volume adjustments seemed to respond just the same. If there was any difference made, I've not the experience to spot it.

I checked the valve lash and when cold, all the rockers were TIGHT on the tops of the valves. I adjusted them to 6 thou as per my service manual and spent an hour and a half checking and rechecking them to make sure I did them correctly. Car seemed to run a LOT better and was a major improvement. Started more easily and I could save it from dying out would it start to sputter out giving it some throttle.

Next is the distributor and timing. The dist that's on the car is a 113 905 205 AN. Someone installed the gear 180 degrees off so i carefully removed it minding the shims and set it back to where it should be. Took a while but the only timing info I could find on this unit was 5 degrees ATDC while idling between 8-900 rpm. Couldn't get it to start whatsoever. Set static timing to 0 degrees and it ran horribly and for a short while. Static timing once again I set it at 7.5 BTDC and it started right up. Using a timing light I borrowed I tried to adjust the timing to 5 ATDC and it wanted to die right away. I rotated the dist the other way and it kept wanting to run better and better far beyond 7.5 BTDC. However, no matter where I set it, giving it some throttle would cause the motor to hesitate and die out.

I've checked the spark plugs too and gapped them. All of them have spark. I bought new plugs just because and am waiting on those too. I also cannot find any proper vacuum diagrams for this california model 74 beetle. Every single picture I find is different and I can't trust any single diagram or picture. I'm kind of at my wits end here trying to get the car to run right. I don't know anyone that knows these cars well enough to help me sort it out and am hoping someone here can maybe steer me in the right direction.

[kpf]

Welcome to the samba!

The AN distributor should have a 4mm ID vacuum hose from the front (towards the front of the car) side of the vacuum canister to the rear of the carburetor. It should also have a 3.2mm ID vacuum hose from the rear of the canister to the left side of the carburetor. I’ll post a picture of the vacuum hoses on my car (1971, but it uses a similar distributor with two vacuum hoses).

You should verify that both sides of your vacuum canister are still working. Use a vacuum pump to make sure they both hold vacuum without leaking. The trouble you’ve had with the timing makes me think that the retard side of your vacuum canister is not working (or not connected correctly).

Other things to verify:

- Is the point gap (dwell) set correctly?
- Is the condenser on your distributor healthy?
- Are the spark plug wires healthy?

Good luck!
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1971 Super Beetle

[tasb]

After fifty years you need to verify that you are getting vacuum advance and retard from that canister. Failure is part of their life cycle. Once you determine if you have both, only one or none we can help you time your spark correctly. The mechanical advance can also create problems with being sticky on advance or returning to idle timing.
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Roads Scholar &
1957 Kombi low mileage 36 hp governor equipped M 178 Slow Drag Winner 2014, 2015, 2018

1965 hardtop Deluxe Microbus owned since 1990 M 620 factory 12 v 1500cc

1961 (October)Single Cab- Road Trip Workhorse

[GBodyVillain]

The points on the dist have been replaced a couple years ago and not used so still relatively new. I reset the points as per the service manual I have. I have tested the condenser and it seems to be doing good. Tested the plug wires and they look old but test well. I ordered another set just to have that covered. I tested the vacuum on the dist and the retard side is fine. Advance side however leaks a ton. When I have used a timing light and gave more throttle, it would advance at what seemed a consistent rate with which I was giving gas. I'm having trouble finding information or even parts on this distributor. Any of you guys know a source I can get parts from for this dist? Is it even possible to replace the vacuum canister? If I need another dist entirely, what would you guys recommend? I've read the 009 is pretty common however has some issues being centrifugal advance. I was looking at the pertonix SVDA #186504 if I wanted to go with something a bit more modern. Thanks for the reply guys.

[kpf]

I’ve had better luck with restored original parts than aftermarket. One source of original parts is vwnos.com, or check the classified section here.
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1971 Super Beetle

[VW_Jimbo]

I just read through your symptoms and think you got a vacuum leak. Have you retorqued the carb flange nuts? End casting nuts? Then, check the throttle shaft for excessive play. Next up take a good look at the manifold boots. If everything checks out visually, move onto a functional test of the system. You need to check for any vacuum leaks. This is a big one, on these cars. Let’s hear what you find!
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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!

[GBodyVillain]

Got another vacuum canister from another user here and now the retard side of the canister no longer leaks. I checked the manifold boots and they're still good. I ran the car again and tried to set it at 5 degrees ATD and this time it woudl stay there but just ran absolutely horribly. I checked everywhere I can think of for vacuum leaks and the only place I could find any sort of leak was on the rigth side of the carb throttle shaft when I sprayed a bit of starter fluid on it. I ended up putting an o ring there and crushing it enough to get the leak to stop temporarily then ran the car again. Didn't have any effect that I coudl detect on how the engine ran. I inspected that side where the throttle shaft goes and it looks like it has already been bushed before.

[GBodyVillain]

Also I did retorque the carb flange nuts. Can't reach the end casting nuts with any of the tools I have, just barely tight enough to prevent me from getting onto the nuts much less turn them at all.

[Cusser]

[mouser98]

[MuzzcoVW]

I second check the fuel pump. Also you say the valves were tight...thats not good. It would be a good idea to do a compression test. A burned valve will cause all sorts of idling and run issues

[GBodyVillain]

Been a while since an update, been super busy with work. Got around to checking compression and cylinder 3 has a major leak, but it seems to be the spark plug threads. If i move the compression tester hose around I can hear it leaking more. The other three cylinders didnt do this, no leaks at all. So I have someone that can help me get the head off and helicoil the spark plug hole, just gotta drop the motor out. I really hope this issue is THE issue. With all the multitude of issues ive found on this car, unplugged vacuum lines, tight valve lashes and rat chewed spark plug wires amongst some other things, it just impresses me to no end that this car would run at all. Fingers crossed on this.

P.S. the fuel pump is fine, works great. Took it out and inspected and tested it. Seems to be in working order. When I changed the oil I didn't smell any gas at all.

[heimlich]

Once you have your engine out you can check everything outside the engine. These engines are fairly easy to start outside of the car. Just set it up on some blocks and stick some fuel to it.

Check the rubber seals on the manifolds when you put the new head on. There are two (one on each side) of the carburetor. These leaking make it harder to time.
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