View Single Post
Armon Armon is offline
Registered User
Join Date: Nov 2012
Location: Virginia Beach, VA
Posts: 6
Unhappy 86 Porsche 944 idle fluctuation

I need advice on my 944 idle fluctuation problem. It started about 3 weeks ago and now I'm starting to second guess myself. I brought the car in 1999 and I have probably replaced and experienced just about everything that normally goes wrong with these cars expect for idle and fuel problems. About two years I had a head job done and almost everything that was old and needed to be changed was replaced. New injectors, hoses, plugs, wires, cap, rotor, fuel filter, etc...

The car never ran better until about 3 weeks ago I pull in the driveway, turned it off and suddenly remembered that I forgot to go to the grocery store. When I started it back up the engine started fluctuating badly, up and down, between 600 and 800 rpm, back and forth. When cold it does the same thing, just after a minute or so after starting.

Immediately I thought vacuum leak, since most of fuel items should still be good. I couldn't find any leaks, most of my hoses were replaced anyway. Next, after reading the posts on here, I check the fuel pump, fuel delivery, temperature sensor, TPS, fuel pressure regulator, air flow sensor. I also rechecked the injectors, plugs and wires. Everything checks out and is within specs.

Oh, I replaced the ICV and that didn't fixed the problem either, however for some reason I notice that when I cramp the hose coming from the J-Boot the engine idles normally, like it suppose too.

Anyway, I'm almost at the end of my rope! I was going to buy a 02 sensor next, but I have already spent enough trying to figure out this problem. If anybody has any other suggestions or ideas on what to check or might be happening then please let me know. Thanks
Old 11-11-2012, 10:01 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)