Help! Car won't idle

[Beeble1]

So for whatever the reason, my 73 won't idle. When you first start it it runs ok, but once it gets warmed up and the engine speed drops to idle, it sputters and dies. I attempted to adjust the carburetor per the Bentley manual, but it didn't help at all. Both the volume control screw and the bypass screw seemed difficult to turn.

Also, sometimes when you try to rev the engine it hesitates first. Not always, but sometimes.

Any ideas on what to do next?

*It has a stock 34 PICT 3 carb.
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Beeble1, ‘73 Super (o\_|_/o) 1600cc w/ Dealer A/C
Beeble2, ‘13 Beetle 2.5L Daily Driver

Dealership items from Bishop-Wayne Volkswagen & Turner Volkswagen in Kankakee, IL wanted

[Danwvw]

Yeah, those adjustment screws have o-rings on them that need to be removed cleaned and greased to help them adjust right. You could also spray in some carb cleaner while they are out. It could be something simple adjustment wise! Make sure the timing is set right and is advancing. Most of those dual vacuum advance distributors are dysfunctional for the retard and that line can be by-passed if that helps. Also you may have the vacuum lines to the wrong place on the carb. When they are right they can be dialed in to both idle and accelerate smoothly without difficulty. Check everything Points, Gap, Timing static 7.5 - 10 degrees advanced will be well over 34 degrees with the vacuum lines hooked up but just around 30 degrees with no vacuum advance. Adjust the valves too if you suspect they would be way out of adjustment. Valve adjustment can effect idle etc. If its getting too hot or not hot enough on the carb pre-heat that effects idle. Also stock oil bath air filter needs to be properly working with the pre-heated air thermostat working so the carb does not get too hot in the summer or too cold in the winter.
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1960 Beetle And 1679cc DP W-100 & Dual Zeniths!

[jarmchairpilot]

If you have a stock manifold the heat riser tube is probably blocked with carbon and will need to be cleaned out-not an easy job.Thats common on old stock vw single port engines.On twin-port engines a common problem is an-air-leak due to a split manifold boot,this is not always easy to see.
A third common problem to look for is a worn spindle in the solex carb body where the butterfly-throttle wears causing a little air-leak.

Make sure to only use high-quality gaskets and seals,most problems are caused by fitting replacement parts(often poor quality made-in -china crapola)so try and buy good quality German made vw parts,ehlring make the best gasket sets at the moment.Bosch ignition parts are tops esp. spark plugs i.m.o.