My VW bug BITES!

My 1969 vw bug will crank, but it won’t STAY cranked without continually revving the engine. I have followed the Chilton’s instructions for adjusting the automatic choke to the letter, several times. This is the car my wife learned to drive in, so its much more important than me. Help.


Have you checked to see if the choke is working? I know you adjusted it. These electric chokes have a coiled bi-metal strip that heats up and causes the choke to open, over time. I am wondering if even though you adjust it ( I think I remember aligning some marks on the outside, right?), it is staying open inside when the engine is cold and needs choke (richer mix, more fuel). When you rev the engine, do you mean pump it? Each pump sprays a little gas down the throat of the carb through the accelerator pump’s little brass tube. That supplies the extra fuel that the choke should provide.

With the choke adjusted and the oil-bath aircleaner removed, looking down the carb, you should see the choke almost closed when the engine is cold, not wide open. You might have to blip the accelerator once (can do it at the carb) to get choke “closed” ( I remember little “steps” that hold the choke’s position until you blip it, once).

These elements do burn out. I would also check the wire going to it and make sure you have juice. See if any of this helps and post back.

Good Luck!

P.S. I wonder if partially covering the top of the carb (like a choke does) with something flat would keep it running? If it does then I think it’s a choke issue.

First off, toss the Chilton’s book. They’re not that great for a “normal” car and they’re really inadequate for something as unique as an air-cooled VW. You’ll need to pick up two books, the Bentley publishing co’s service manual for your car which is a superb model-specific technical service manual and John Muir’s “How to Keep Your VW Alive: a Guide for the Compleat Idiot” which is sort of a half-service manual half comic book and half philisophical tract that is a must-have for any air-cooled VW owner.

If you’re saying the engine will simply not idle at all but will run fine if the throttle is depressed (say at least a 1/3 of the way) then you should suspect a problem with the anti-diesel solenoid on the carburetor. Assuming it still has the original on it.

If power is not provided to that solenoid or the solenoid is defective the idle circuit in the carburetor will be shut down completely.
Turn the key the the ON position, disconnect the wire from the solenoid, and lightly touch the solenoid terminal a few times. You should hear it click each time. If not then verify power is provided to the solenoid.

This ia also a common problem with the old VW air-cools when age sets in on them.


Muir’s "How to Keep Your VW Alive

That is a great book. It is worth the cost even if you don’t own a air cooled VW. It is a fun read. It will cover the OP’s problem as well.

BTW I it does sound like the choke.

What is the history of this problem?  When did it start?

John Muir’s book is indeed a great one for maintaining the old air-cooled VWs. It is very readable, as well as easy enough for even the novice mechanic to follow. I relied heavily on that book in order to keep my Karmann-Ghia working properly, and the book never failed to help me when I needed to repair something on that car.

However, I do want to point out that Mr. Muir was not a fan of automatic chokes, and he actually recommended that one deactivate the choke on their VW bug. In the book, he gives his alternate starting procedure, followed by a brief warm-up of the engine, sans automatic choke.

There may be an intake gasket leak or a vacuum line leak. If I remember, this car only has one or two vacuum lines. If a leak cannot be found, the carb may need to be rebuilt. Have you tried to boost the idle by adjusting the idle speed screw? Does this work? Is the choke linkage bumping up the idle when cold? Does it idle once warmed up? I think chasing the choke adjustments is a red herring. There are lots of other issues here.

Wow! You’re taking me way back.

We did sell quite a few of those when I worked for VW quite a while back.
I used to know all the part numbers in my head. I’m thinking…113 129 413B, maybe?
Isn’t that sick that I still carry around some of the numbers?


If I recall, this is located where the only other wire (besides choke wire) going to the carb, attaches. It is cylindrical, maybe a couple inches long. They unscrew and earlier models like this have a jet in the end, I believe. Later models (71?)had a plunger.

If the choke test doesn’t work, then this is a suspect.

I have Shop manual and even original Parts catalogs. If this doesn’t work then maybe Narcosis can let us know and I’ll see what else comes up.

P.S. I was incorrect. It was 111 129 413B, sorry.

Narcosis needs to give us more info.

Mr. Narcosis,

By “continually revving” do you mean holding the throttle open, above idle position or pumping (blipping) the throttle continually?

Mr. Narcosis,

Was this car running just fine the last time it was driven?

How long did it sit after that?

Does it idle after warming up, as Busted Knuckles asked? Or can’t you keep it going long enough to find out?

Tell us about revving. See above.

I’m thinking if it worked fine and a short while later, it didn’t, then just one little thing might be the problem, like choke or idle solenoid and I wouldn’t mess with everything. If it sat a looong time, who knows? With more info we can go from there.

The reason why I wasn’t able to offer more constructive advice is that I’ve never actually worked on an air-cooled VW that hadn’t been “Muir-ed” over to a manual choke.

Thanks to all who responded. It was the anti-dieseling apparatus… apparently it can wiggle loose over time. So, all it took was a few turns of a wrench!!