Mark944na86

Here's a weird thing -- only started in the last few days.

On a cold start, the S2 idles fine on start up, and fine for entire trip all the way through to normal operating temps.

On a warm start, however, the car doesn't want to hold idle; and I need to keep the revs up until the car has been driven for a few minutes, or it will cut out. Once running at normal temp, idle is fine again -- holds rock steady at just under 1K rpm.

What does this sound like? It's strange -- get in the car in the morning, drive someplace -- no probs. Come back to the car while it's still warm -- doesn't want to hold idle (until the car has been driven for about 5 mins.)

As I said, only just started happening in the last few days.

Luis de Prat

Hey there. Try disconnecting the airflow sensor (aka airflow meter) plug and reconnecting it. It's on the lower left hand side of the sensor.

If this doesn't do the trick, it could be a number of things but if the car drives fine but won't hold an idle when warm, I would suspect the idle stabiliser valve is either dirty or leaking. It's located right under the intake manifold. You can take it out and clean it with solvent or patch it up with silicone sealant if it's leaking.

Let us know what you find!

Mark944na86

Thanks, Luis. I unplugged/reconnected the AFM plug, but haven't had a chance to test... the car is on stands as of today while I'm waiting for my a/c compressor to come back resealed/rebuilt (hopefully!)

It won't hold an idle upon first start-up when warm, but will hold idle once at full operating temp. Does that sound like a ISV to you?

Luis de Prat

Yes!

Mark944na86

Update: This warm idle problem has disappeared after changing belts, a/c compressor and front oil seals.

So yet another fix for the archives for idle problems...

me97ggl

woww.....this can be the solution to my problem i guess

I have recently purchased a 944 S2 that's been sitting for a long time, for sure it needs timing belts and rollers/pulleys etc (which are on the way) and i also have idle problems while cold start. After 10 minutes of periodicly droping the revs from 1000rpm to 200-300rpm (almost dies) then when you press the gas, it idles nicely.

I just cannot see how the timing belts can effent the idle issue

any help on this?

Mark944na86

Sorry, I wasn't being completely serious -- the problem _did_ mysteriously disappear after I got it back together after the above repairs, but what it was that changed I really have no idea -- perhaps simply disconnecting/reconnecting the AFM as Luis had suggested (the AFM needs removal when doing a belts job) did the trick? Who knows.

It was a nice bonus after getting things back together again to find the problem had resolved itself (at least for the present.)

BTW, get the belts and rollers attended to ASAP -- it may not fix your idle issue, but well worth doing anyway. A set of bent valves wil also fix your idle issue, but probably not in a way you'd be pleased with...