Good afternoon
I’m new to group. 1999 996 911. Have an idle problem. Cold is great until warm. 650-700 rpm. AC on 950 perfect when warm. AC off back to 650-700. I changed Crank position sensor, Warm up valve on throttle body. Removed and Cleaned intake manifold. No codes. Runs great , 78000 miles. Oil cap and filler tube appear to seal. Any ideas please would help.
thanks!

 

Also have a 3.4 car. I’m guessing you’re not seeing any present codes to do a basic scan? Rough idle, I always look at the MAF sensor, but usually it should be accompanied by a code, however it could be on its way out. How does the battery voltage look when running? Sometimes the voltage regulator behind these alternators can be funny as well.
Do you have any brief smoke on cold start up? If there’s any symptoms there, id look at a possible bad Air oil Seperator replacement. If your oil cap is hard to remove when the engine is running, you may have an AOS problem- that’s an easy way to attempt to test it. AOS is fairly common replacement on these cars, I know someone was looking at creating an AOS solution.
Also double check the coil packs, if they are the older style units with a 996 part number vs 997- there could be some stress cracks, possibly causing a weird hunting or low idle if they are arcing. Let me know if any of this helps get you started or pointed in the right direction. Welcome to 6 Speed!

 

Good afternoon
Well as far as startup warm or cold NO smoke at all. I will try the cap trick. Does the handbrake affect anything as far as startup as was hard to get running yesterday when run after an hour drive and parked 15-20 minutes. Could the Fuel filter be a case? I try to troubleshoot with the easier things first. Also carbon canisters? I appreciate your help. I keep plugging away at this. Stand by.
best regards
ConnieD

 

Handbrake should have no affect at all. I would definitely look at the fuel filter, do you know the last time it’s been changed? I do mine every few years regardless as cheap preventative maintenance. The fuel pump could possibly be on its way out too, but I feel most of these cars tend to get more mileage on them before we see many fuel pump issues. Hopefully all injectors are clean and spraying freely too. There are a lot of specific components that can cause the hard start issues, but the more you can rule out without throwing parts at it, the better. If you’re still stuck after troubleshooting all the basic items, it certainly wouldn’t hurt to have a good private mechanic take a look over the car at your local Porsche shop. I’ve not ever had any issues with the carbon canisters on either of my 996 cars, but maybe others could weigh in.

 

Have you had any luck with your troubleshooting?