Increasing idle on 964 due to stalling

[indigowhale]

1990 C2 keeps stalling probably due to lightweight flywheel. It does it at lights and stop and go traffic.

Where is the screw to increase the idling RPM, is it the throttle flap stop screw or is there an air bypass screew (in addition to the AFM idle mix screw)? I am supposing that one exists.

Many thanks in advance.

[mede8er]

Here's some good info.....

3.6 liter conversion stalling at low speeds

I did the ISV surgery and adjusted it counterclockwise which made the idle tolerable......But for my 993 conversion I ultimately used a Rennsport chipped DME fro Steve Weiner and now my car idles silky smooth....

[RSlater]

My 90 C2 was doing the same thing (I also have lightweight flywheel). It took JW about 5 minutes to fix. Turned out that the micro switch on the linkage just needed a minor adjustment

[indigowhale]

Thanks, that links has all the information I need!

Am I assuming correctly that the ISV is not adjustable from the factory and that a little surgery will make it so?

TIA.

[Bill Verburg]

Am I assuming correctly that the ISV is not adjustable from the factory and that a little surgery will make it so?

Correct, there are 3 x2.5mm(IIRC) hex head bolts buried in epoxy, you will need a dremel to clean out the epoxy.

The 964s have a microswitch which 993s don't have i would start w/ that.

Also check for vacuum leaks