Warm Starting Issue with 3.2

[bkporsche]

I am having an issue with my '84 911 with a 3.2 engine. If I start it cold, it starts right up. Once warmed up, if I turn it off, then try to start it right away, (say within 5 minutes), there's no problem getting it to start. But if I let it sit for 20 minutes or longer, it takes 3-4 good cranks on the starter to get it to fire up.

The head temp sensor was replaced by PO about 7k miles ago, and it has been completely tuned (new wires, plugs, rotor, dist cap, valves adjusted), injectors rebuilt and a new fuel filter put in place 5k miles ago. The car runs great otherwise.

I suspect that it is a fuel pressure regulator. Any thoughts?

[jlex]

I had the same problem w/ my '85. Turned out the fuel pressure wasn't holding up (I think it's supposed to hold at 14 psi after shut down). I checked it out w/ a fuel pressure gauge & found it dropped to 0 just a few minutes after shut down.
When it does that, it's one of two things: either you have an injector that leaks gas into the cylinder after shut down, thereby bleeding pressure off, or the check valve on your fuel pump isn't working & pressure can't hold in the line.
My problem was solved when I pulled my injectors & had them cleaned (Witchunters did it). After cleaning & re checking, pressure was holding at the proper level & my starting problem was gone.
Good luck.

regards,

jlex.

[bkporsche]

Thanks for the reply. Since I had my injectors rebuilt last year (in hunting down an inconsistent idle problem), I am going with your other suggestion, the fuel pump check valve as the culprit.

Regarding the fuel pressure gauge, did you need to get an adapter to fit to the fuel rail? I have a fuel gauge for use with other cars, but none of the adapters seem to quite fit. Let me know if you have a source.

[jlex]

I had the same problem as you re the adapter. Craig, a poster here under the name of Cgarr, fabricated one out of aluminum for me. I can send it to you if you send me a PM with your address.

regards,

jlex.