Engine idles really high after coming to a stop

[vridaw]

Hi guys,

I have a 63 Beetle with a 1200cc and a Solex H30-31PICT carb.

Whenever I gear down and come to a stop at a red light for example, the engine would be reving itself at what sounds like 2000RPM. Which makes my motor heat up pretty damn quick as you can imagine. To bring it back to normal, I have to pinch the throttle quickly to bring it back to normal. The hotter it gets the harder it is for it to come down to normal idle.

Any ideas on how I should go about diagnosing this problem? The car runs fine otherwise.

Thanks

[mukluk]

Sticking throttle? Vaccum leak?

What do you mean by "pinch the throttle quickly"?
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1960 Ragtop w/Semaphores "Inga"

[vridaw]

I'll check if the throttle is sticking. Good idea!

What I mean by pinching the throttle is just giving the motor a quick rev with my foot. It usually makes the engine come back down and rev at the normal 900rpm

[mukluk]

Ah, never heard it called that before; always refered to that as tapping the throttle if you don't press down far, or a quick jab of the throttle if pressed down further.

Most likely a sticking throttle then. Check that the throttle shaft of the carb moves freely and that the bushings aren't worn in the body. Speaking of which, how old is the carb? Also, check the throttle cable and linkage at the pedal for binding. If you can't remember the last time the cable was cleaned and lubricated, now would be a good time to do so.
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1960 Ragtop w/Semaphores "Inga"

[vridaw]

You hit the nail on the head my friend! Sticking throttle

Sometimes it goes back all the way, sometimes not. I'll lube all the parts in that and tinker with it.

Thanks for your help!

[Aynthm]

There's a small pin in the stepped throttle positioner that probably fell out due to vibration. Get a small nail the proper length and superglue it into the hole as it acts as a stop to keep the stepped positioner from flipping completely over causing the racing condition. Red arrow

[theblake]

[vridaw]

Hey Aynthm, thanks for pointing that out. I actually have that pin, but it seems like it's the other throttle piece that is sticking and not going back all the way. I have yet to attempt to fix it..but I will tonight.

[KTPhil]

Lube is temporary. Be sure to straighten, smooth and debut everything first. And check the cable and pedal assemblies in the same way. The trouble may not be at the carb itself.

[jzjames]

[Aynthm]

Check the cable down by your pedal as it enters the tunnel, some have a red plastic coating there that can hang up on the entrance into the tunnel.

[Eric&Barb]

[pwmcguire]

[Jon Schmid]

If it's still idling high after you've checked the throttle linkage, check your distributor (assuming stock ignition). The advance weight springs sometimes weaken and the timing won't retard all the way back at idle, especially when the engine warms up. Just a thought.