auxiliary air valve idle issue...not exactly

Kings911 · 08-10-2017, 10:32 AM

Wonder if this has happened to any early 944 NA owners out there.

My 83 has been running amazing for the 1k or so miles I have driven it.

Then one day I start it up for work and again it is amazing until about 10 minutes into my drive. Then every stop light I hit the car almost dies but then gets a steady idle around 3-400 rpm.

I drive the car 3 more times. Again it idles at 3-400 rpm but once in motion the car revs and drives amazing. Hit the next stop light and boom 400 rpm.

I see another poster say that they removed the AAV without removing the intake manifold. So I grab the tools he recommends but I can't quit get a straight shot on the bolt.

So I think to myself "if I pull that spark plug wire off the plug I could get a bit more room". Well the wire pulls off the plug basically with no resistance. I think to myself that cant be right. So I pull the others and sure enough the make a snap noise when pulled with quit a bit of pressure.

So I snap all the wires back on tight. Fire the car up and it has been 100% fine for the last 50 miles of hard use.

So I assume what was happening was the plug wire was loose and at idle wasn't getting spark so the car was idling on 3cyl? But when I revved it up the spark could jump across to the plug?

Well if that's the case and not just a coincidence I was very lucky I couldn't pull the AAV out with the wire and manifold in the way!!!

v2rocket_aka944 · 08-10-2017, 10:54 AM

hopefully that fixes it...
but FYI, the AAV only helps the early 944 on cold starts - by your 10 minute mark it is closed and not really doing anything anymore.

so if the problem does persist you need to check for vacuum leaks or maybe adjust the throttle stop/idle bypass screw.

Kings911 · 08-10-2017, 12:08 PM

So if it was bad it would just rough idle when cold but then clear up?

I should tackle vaccuum lines anyway given their age.

djnolan · djnolan's Garage

I don't think one wire would make that much difference, did you push all of the injector plugs on good too? Push the wire, not the shell...

Kings911 · 08-10-2017, 02:12 PM

Quote:

Originally Posted by djnolan

I don't think one wire would make that much difference, did you push all of the injector plugs on good too? Push the wire, not the shell...

The only thing on the car i touched was the one spark plug wire. And since doing that the idle is nice and smooth.

I wouldn't think one wire would cause that much of an issue.

I guess I could just try and recreate the issue. By pulling the wire and putting it back in losely/gently