Anyone have their engine stall or die out approx 200-350 RPM within a second of a cold start? It then regains it's RPM and runs ok. It won't repeat unless it sits overnight or is immediately turned off and let sit for at least an hour. It starts very quickly, it's just that it has this problem as if it starves for fuel for about a half second. This happens all the time. Even tried different fuel and starting with A/C on & off.
'First
Porsche
' Man
Edited by - Cayman_S on 09/21/2006 10:53:25 PM
Nope. Does not sound right. How is the ambient temp in this condition?
Could be a couple of things......
Bad or uncalibraded MAF (Mass Airflow Meter)......dealer should be able to find this pretty quick and either fix or replace. They usually are replaced if suspect as this is the path of least resistance.
Bad fuel pressure check valve. There is a small check valve in the fuel line that keeps fuel pressure to the injectors high even when the car is shutdown. Usually restarts after a few minutes of downtime are not a problem as the fuel pressure doesn't have that much time to leak down through the bad valve......but if it sits for a longer period of time, enough fuel pressure can leak down causing some hard restarts........this is what seems to be happening. A good dealer should be able to take care of this quickly also.
Thanks for the help. /fckeditor/editor/images/smiley/MWPX/thumbsup.gif Now I can ask about these things you mentionedto see what they say. But most likely I suppose I'll have to ask the regional tech to look at this too (A/C issue too)when he comes in since the dealer just told me they couldn't find anything wrong. They even tried to tell me that all CS's do this. When I pickupmy CS I'll see if they are willing to get a key for a couple of cars on the lot and show me that they all have this issue.
BTW, This does not seem to be affected by the outside air temperature. I've only had my CS for 10 weeks now and in San Diego the coolest temp has been about 60 deg (if you want to call that cool). But this issue was happening even when the temperature was 95 deg.
'First Porsche' Man
My previous
Porsche
was a 996 Coupe that after sitting for over 4 or 5 hours would be hard to start. It would rev to 1000 - 1200 rpm initially and then almost immediately drop to about 600 rpm and would be on the edge of dying. If I tried to give it gas at that point it would die. If I waited for a few seconds it would suddenly go back to 1000 - 1200 rpm and stay there while it warmed up a little and then drop back to the normal 800 - 900 rpm idle. It was almost as though it didn't realize it was starting from cold. I always wondered if there was a problem with a temperature sensor or something. My dealership also gave me the 'Thats the way all
911s
are', and I could never find a time where they had an 02 996 on the lot that had been sitting overnight to try and see if it was true. I don't know if this is similar to your problem or not.
Yes!! That's close to it...although it doesn't get to thepoint where it almost dies...at least not yet. It starts very quickly and then goes to (I think) 1400 RPM...then just an instant later dies down (starves, sputters, chokes)to 1050-1200 for just asecond or so, then returns to 1400 RPM for a short time and goes to it's normal idle speed. It's not something that I can't live with...I just thought with the finely tuned engine and the super computer that does just about anything one can imagine that it shouldn't do this. I haven't experienced this misbehavior since I had a carbureted engine...and then I adjusted the automatic choke and got rid ot the problem. The dealer said they found no codes. I guess if the computer doesn't flag a problem...then there must not be a problem. I'm disappointed in that. What happened to good old fashion troubleshooting? If this is just a characteristic of this engine/computer...I'll be able to live with it...just thought a car of this price and caliber would run as good as my Chevy's...the fuel injected one & the carbureted one.
'First
Porsche
' Man
Edited by - Cayman_S on 09/22/2006 07:46:42 AM
Unrelated but interesting: On our Merc if the key is in with engine off put foot on the throttle, foot off, then start, it revs up a lot when it is started!!!!Of course dont press the pedal before start and its ok.Dumb thing buffered the pedal signal and applied it way later!!! Good grief, da softwares got bugs. I think we blame
Bosch
for this?
