I hate to post this but I have to ask.

[jbrinkley]

I get this cold start idle that runs up to 1200 then back down to 900 RPM. Does it five or six times, real qiuck, then normal idle speed. When warm it idles fine. Runs well, no flat spots.
Only thing I've done is turned idle down, maybe one turn, with test plug jumped (B&C) O2 sensor unpluged, normal operating temp. No change in problem before or after adjustment.
I've searched and searched and searched, everyone else seems to have a warm start idle thing.
Any help would be great.
thanks
87' 3.2

[jgporsche]

Does it start up on first crank or turns over about 10 seconds, then starts? With AC on does the idle stick occasionally 1200 RPM? I had a clogged fuel injector that was hard to locate. Untill it was plugged completely was it easy to find. The gaskets on the intake manifolds are suspect also.

[scottb]

Mixture?

[ZOA NOM]

I'm fighting the same problem. Vacuum leak seems to be the most likely culprit. I've been replacing hoses and clamps like mad. I even spent a fortune on refurbishing my AirFlow Sensor. I'm much closer than I was when it started. I can get it to quit pretty quickly with the idle adjustment.

[jbrinkley]

Abbeville, starts on first try A/C or not, intake bolts are tight, injectors seem/ feel fine but I haven't checked them. Would a clogged one make a ticking sound? I didn't really want to get that far into it just yet. I dont't suppose you know a mechanic close by? I'm in lafayette.

Mixture is next, for some readon I cant get a good reading on DVM from o2 plug, it's the three wire o2 plug and all i get is .1
maybe I'm doing it wrong?

[jgporsche]

Does it start up on first crank or turns over about 10 seconds, then starts? With AC on does the idle stick occasionally 1200 RPM? I had a clogged fuel injector that was hard to locate. Untill it was plugged completely was it easy to find. The gaskets on the intake manifolds are suspect also.

[jbrinkley]

Also, can someone tell me how to get the plug out of the AFm screw hole? I tried to pry it out with a knife,,,,,,, NOT
I've searched for that also, no luck

[jgporsche]

Not sure why my post appeared twice. Checking injectors are easy. Just unplug one at a time and see if it runs poorly, just don’t lose the little metal clips. I changed my oxygen sensor / head temp sensor but didn't help. My gaskets were shot and the black spacers beneath had cracks in them. If you never changed those I would take a look, they deteriorate with heat and age.

Don’t know of any mechanics. I do my own work, that’s the joy of owning a Porsche. And occasionally I fix more than I break!

[djmcmath]

Not sure I'm totally familiar with the AFM screw hole, but it seems like I haven't found a lot of screw holes that I couldn't persuade pieces out of by using a handy-dandy magnet. Seems like my magnet came from the local Schucks, for about $6, and has saved me from flipping the car upside-down and shaking vigorously several times.

Dan

[jbrinkley]

thanks, I'll try that. I read just a minute ago that it's metal. Here I was trying to pry at it with a knife, like it's rubber.

[911-32]

Funny, my 89 did the same thing and got progressively worse over a period of time ie., the idle took longer and longer to settle. I was told it was the airflow meter that needed to be replaced and that they just wear out over time. I got a used one from a low mileage 964 and problem solved for about 2 years. The replacement is just starting to do the same now but just 3-5 blips before it settles down to steady idle. I can live with that for a while.

HTH,
Richard

[dickster]

mine's always done that. not a problem - for me anyway.