Idleing too fast

[epete]

I have a 1999 Porsche 911 Carerra. It's idleing too fast - about 3K when started. I can go back in the engine compartment and pull the throttle cable down to meet the idle adjustment screw and then it slows down to a respectible 1K rpm, but it's as if the cable is too short. There seems to be some sort of adjustment at the pedal, but I can't seem to turn the knurled knob there. I think my problem is just that the cable is too short and I need a way to length it or adjust the cable so the idler cam falls against the idle screw instead of being pulled out a bit.

Anyone able to help me on this? I'm afraid I'm just an amatuer "wheeler dealer mechanic"...

Thanks

[logray]

I've had this problem before however both times it was due to an improperly routed cable after transmission and/or engine reinstall. It can't bind anywhere and has to go directly over the top of the engine straight to the T/B.

You might check that the cable housing end hasn't separated from the cable tube behind the throttle body, which can also shorten the cable.

I do need to change my cable as it is starting to fray near the T/B.

edit: you may also want to check your idle air control valve (IACV) to make sure it isn't gummed up and also throttle body butterfly to make sure it isn't binding.

Edited August 4, 2011 by logray