Ruff Idle for in my 1986 944....

Crrraaiig · 07-01-2003, 02:46 PM

Hey guys. This is my first post on this board and I have to say, thank God I found it.....cause I'm sure I'm gonna have a lot of questions about this car...

Alrighty, I've got an 86 944 that I've just put new belts on (timing cam, etc done by a shop) and new motor mounts. The thing idled pretty bad before I did these things and now idles a lot better. The problem I have now is that when the AC compressor is on, and I'm idling at a stoplight, the thing idles very rough. It chokes the RPMs down to like 750 and I'm sure even a new one would shake at that RPM. It also does this when the engine is very cold but living in Dallas, TX I have'nt had to deal with that in awhile. Otherwise, when she's hot or the AC is off, she purs..

I just had a mechanic replace the AC clutch and he said there was no sensor that could be bad and there was no way to adjust the idle.

Any ideas???

Also wondering if its just me, or does a red Porsche with a black dash not ever seem to really cool down when it a 100 degrees outside? Just wondering if its the nature of car or if I need to add a shot of R12?

Scott R · Scott R's Garage

The 86 actually does have a system for stabilizing the idle when the A/C is on. It uses an idle stabilizer unit between the 3rd and 4th intake runners. Sometimes it gets gunked up and does not funtion coirrectly.

I have also now seen one of these idle units that was not seeing a signal from the DME to the unit due to a broken wire harness. At any rate it should be keeping the idle stable. When I turn my A/C on it dips for a second and then returns to normal when the stabilizer adjusts it.

Crrraaiig · 07-01-2003, 03:05 PM

Hey thanks Scott,

BTW, What are intake runners and where can I find them?

Scott R · Scott R's Garage

The intake runners are silver on color and run to the head on the passenger side. Track backwards from the air filter box, you will come to the throttle body first where the accelerator cable attaches, the throttle body is bolted to the intake manifold, and the "runners" are the individual intake tubes that comprise the manifold.

Lawrence Coppari · 07-02-2003, 08:19 AM

Scott,
Do the turbos have the idle stabilizer or compensator? I've had my intake off a number of times and don't see anything there other than the cycling valve. Could you take a picture of it and post it?

Scott R · Scott R's Garage

My 87 does, and its right in front of the "timing valve" on my turbo, its bolted to the block inside a rubber and metal round bracket. It diverts intake through the valve using two rubber hoses attached to the intake manifold directly across from the #2 and #3 injectors.

Crrraaiig · 07-02-2003, 09:15 AM

I'm not sure if this is any help....but when I first start the car, even if its like 80 outside, it still dips wayyy down in the RPMs and tries to die until its run for about a minute...then it runs fine. Is there an idle adjustment on this car anywhere?

MrPants · 07-02-2003, 03:12 PM

cool another mertroplex member
welcome