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Thu Nov 19, 2009 7:39 am

My '70 bug has the original 30 PICT 3 carb & distributor combination. It was cleaned by the PO about 2 years ago.
Occasionally it dies at idle when coming to a stop. The weird thing here is if you're stopping on a flat surface or on an uphill grade the RPM's stay good & no problems... it's only when the car goes into a downhill stop that you can hear RPMs drop below where they should (then usually recover) before a stall. Sometimes it doesn't recover from the RPM drop & it stalls, never on a level stop, though... just a downhill stop..
I've been fiddling with it for a little while now, trying to make it perfect... last night I reconnected the altitude compensator (mounted on the side of the engine compartment) & now the throttle position valve actually works. I've also set the correct RPM using the idle & volume screws & stepped up the choke a bit. Will recheck timing this weekend & do some more fiddling.
Would narrow my search if someone has an idea or a similar experience that would explain the weird behavior. Thanks.

Thu Nov 19, 2009 8:26 am

a friend, mechanic, vw guru threatened to padlock my carb to keep me from 'fiddling' with it. needless to say, I've had my knuckles rapped with a flathead more than once.

that said- http://www.vw-resource.com/procedures.html - may be helpful in resetting everything back to base-line settings.
would be cautious about anything any PO did 2 years ago. May be that the carb needs thorough 'going through.'
check filters - all of them, in addition to the in-line filter (the one that is not 'supposed' to be located between the fuel pump and the carb) you can check other posts to find if your 70 has a filter at the bottom of the fuel tank.

Check for vacuum leaks - could explain the variable rpm.
I'm sure others can chime in with more *(better) thoughts and ideas.
Good luck in the work.
Rev.

Thu Nov 19, 2009 11:32 am

[quote="Mikedrevguy"]a friend, mechanic, vw guru threatened to padlock my carb to keep me from 'fiddling' with it. needless to say, I've had my knuckles rapped with a flathead more than once.

:D Funny stuff! Sounds like me.
Maybe that Kiefernet guy will tell me what's up. Sounds like he's the carb guru on the board. The only thing I can theorize that would change on a downhill grade would be the level of gas in the bowl.... does anyone know if that's not correct, would it cause a problem? Haven't had any real experience overhauling a carb, but I'm sure its not rocket surgery :roll:
Anyway, if anyone wants to chime in re how to check & adjust the gas level using the float, I'd appreciate it.