No restart when warm after cold start

[pcarenthuz]

I've got sort of a strange situation and want to be sure I include the uniqueness of my '82 911 SC configuration on my 50K mile car:

• 1982 911 SC w/ '84 DME engine (I know, shame on me for this transplant 15 years ago).
• FI; whipple supercharger (SOK)
• Canems LTD 3.2 Carrera ECU @ Canems Engine Management Solutions
• Air flow meter removed; map sensor installed
• New Bosch saturated injectors
• New fuel pump (50 psi on rail)
• New idle control valve
• New spark plugs
• Just recently replaced speed and crank position sensors
• Just recently replaced DME/fuel pump relay

Very recently, after years of running with the supercharger and original ECU and rising rate fuel regulator I decided to move to the Canems plug and play ECU after my OEM ECU died. With this change up I replaced the peak and hold injectors with saturated units and replaced the air flow meter with a map sensor.

I took the car to Frank Smith, a fantastic engine builder and tuner, of Tuning Tech FS in Crofton MD. He got the car dialed in with the new ECU and it was running fantastic. It has never run better and made some great numbers on the dyno. This was about 1 month ago. Recently, however, it's developed a problem.

I can walk out to the car when it's cold and it will start right up. If I let it run for a few minutes, cut it off, and attempt a restart it won't fire. My recent troubleshooting/preventative measures included replacing the speed and crank sensors as well as the DME/FP relay as noted above. No change.

I have spark and fuel while cranking the engine in this no start scenario. I don't seem to have, however, any injector pulsing. I've tried a screwdriver placed against an injector as a poor mans stethoscope and heard no clicking/solenoid sound.

Does anyone have any suggestions? I'm beginning to think I may have an ECU issue despite it being new.

Thank you.

Pat Arnold

[Bob Kontak]

Originally Posted by pcarenthuz

Does anyone have any suggestions? I'm beginning to think I may have an ECU issue despite it being new.

The little bit I know about injectors is that with the key on there should be 12V at one of the injector wire terminals. ECU provides ground.

If you can confirm power to the hot side, it narrows things down.

[pcarenthuz]

Originally Posted by Bob Kontak

The little bit I know about injectors is that with the key on there should be 12V at one of the injector wire terminals. ECU provides ground.

If you can confirm power to the hot side, it narrows things down.

Bob, easy enough to check. Much appreciated.