1991 Porsche 944 starting

1991 PORSCHE 944
98,000 MILES • 4 CYL • 2WD • MANUAL
Avatar
BIGTED
  • MEMBER
  • 1 POST
Hi I have a 1991 944s2 soft top, it starts from cold fine, drives fine, if I stop the engine
Then leave it for an hr or more it starts fine, if I leave it for 5 to 10 mins it starts ok , if I leave it for 20 to 30 mins it just will not fire does not even try, all turns over fine ( it has always turned over quite slow it probably sound as if the battery is a bit flat but its not may be the starter motor needs overhauling ? ) then after trying to start it for around 10 mins it then starts runs a bit rough for 10 seconds or so then can drive off runs fine , I had the car serviced in Nov 2009 , changed the DME relay, new dis cap, new arm, new plugs and leads, cleaned the TDC sensor at top of fly wheel, still does it, on reading forums I think it could possibly be an fuel injector leaking into the bore after stopping the engine can this make the spark plug wet and there for no start ? but I would have through it would have started on 3 cylinders until the engine cleared the un burnt fuel then the flooded piston would fire????? But I am only guessing can u help.
Regards Andy from London SE9
Dec 31, 2009 at 5:46 AM
Advertisement
Avatar
JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Andy:
I agree with your idea. If you had one injector leaking, it would still start, run on three cylenders, and then eventually clean itself out. I need you to check something for me. When this happens, I need to know if you are getting spark to the plugs and fuel to the engine. Here are how to's for checking both. Check this when the car refuses to start and let me know which one is missing.

https://www.2carpros.com/how_to/how_to_test_an_ignition_system.htm

https://www.2carpros.com/how_to/how_to_check_fuel_pressure.htm

If you want, when the car doesn't start, see if it will start with starting fluid. If it does for a few seconds, that tells me it is getting spark and no fuel. If it doesn't start, then the opposite.

Let me know what you find.

Happy new year, and thanks for using 2carpros.com.

Joe
PS: Great Car!
Dec 31, 2009 at 6:01 PM
Avatar
JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
First, thanks for the positive feedback. It's appreciated. Second, let me know what you find, and I hope you get the new seats in. I'm in the process of looking for either a 944 or a Mitsubishi 3000GT. They are both nice cars, but there is something about a Porsche that makes it more attractive to me. Have you had good luck with yours? I'll only get to drive it about 4 months out of the year because of where I live, but it will be fun.

Take care and let me know what you find.

Joe
Jan 1, 2010 at 10:52 PM
Advertisement