pjc

1976, 2.7 engine restoration just completed. Starts from cold, runs just fine but doesn't want to hot start. After about third churn it fires and runs rough for about 10 seconds then OK. Was OK before restoration.

Thought it may be a fuel pressure problem (non-return valve on fuel pump or accumulator) but:

after warming up the engine:

Pump pressure was 4.8 bar; control pressure engine running 3.6 bar, stopped 2.8 bar

After cooling down for 20 minutes pressure 1 bar.

Surely can only be fuel, air or spark? I'm stumped any ideas?

PJC

Peter Zimmermann

PJC: I know that you've done your homework (pressures) but that doesn't always tell the story, or fix the car. Put a reversal valve on the pump, or replace the pump, or replace the accumulator (one of those items almost always fixes the issue). I've had the same deal with early 911 Turbos, there is a pressure diagnosis to determine if the rear pump is bad, the real way to diagnose is to replace the rear pump! FYI, I really hope that everything fuel-related was kept clean while disassembled - there is nothing worse that going after a problem like yours when the fault is a tiny piece of dirt somewhere.
Pete

pjc

Pete,

Yes, everything was kept spotless (cleanliness is next to .... etc on such a job). Looks like I'll have to try replacing a few bits (pump and reverse valve all one unfortunately) but their so darned expensive in the UK - lets hope I hit on the problem at the first bite. Thanks for reply.

PJC