Idle Problem 3.2 Carrera
 

Hi, I have a 3.2 911 1989, not long after I brought it, it developed an idle problem (hunting). Some times it will idle smoothly, but it seems to be getting worse, it happens more frequently and now sometimes to the point of stalling. When it is hunting if you take off the oil filler cap it will return to a normal idle within 15 to 20 seconds. Suggesting a build up of crank case pressure? Any suggestions what might be wrong appreciated.:)

Replacing the CHT on my 3.2 solved the problem for me.
CHT = Cylinder Heat Temperature sensor.

Do you also have difficulty taking off smoothly from a complete stop or stall the engine easily at first startup?

When hunting, leave the car on, open the lid and tap on the Idle Control Valve, if it clears up, you need to remove and clean the ICV with a non-residue carb cleaner until cleanser comes out clear then spray a little silicon lube and insure the internal component rocks back and forth freely. While it is off the car, verify the OHMs on the ICV per bentley.

Have you checked your mixture at idle? You could be a little rich. When you remove the oil cap you are creating a vacuum leak and adding air to the mixture, thus leaning it out a bit. When it's real cold out the CHT will push my car too rich and it will hunt for the first 30 seconds. Just my experience. I'll defer to the pros around here. -J

very common problem - tens of possible solutions - search this forum for related threads

Thanks for answering, I did clean ICV and it didn't change. I guess it could still be faulty. On cold start up it can be smooth idle one day hunting the next, not to the point of stopping but once warmed up sometimes to that point. A little more concentration on clutch work can be required to avoid stalling. Would I be right in saying that it's not possible to change the mixture in a fuel injected 3.2? Also I've just noticed around the tappet cover, possible vacuum leak. I fear I've answered my own question, but talked to a mechanic and said that it may or may not be the cause of the problem. Once again any feed back is greatly appreciated. Thanks

" A little more concentration on clutch work can be required to avoid stalling."

Your symptoms point to over rich running conditions which can be corrected by adjustments to the AFM. A common problem on late 3.2s that is also linked to premature valve guide wear due to high head temperatures.



Cheers,

Joe