280z Intermittently Engine Wont start

[Dave WM]

did you ever test the ign switch as mentioned before, I mean out of the car with a multimeter on tone?

[stravi757]

21 hours ago, Dave WM said:

did you ever test the ign switch as mentioned before, I mean out of the car with a multimeter on tone?

yes, and also swapped it out with a know working spare

I grounded the negative coil wire with the ignition turned on, and the injector will open(confirmed) every third tap. I tried this when the car was not starting by cranking.(edit, fluke test due to intermittence)

EDIT. I tried grounding the negative coil wire again when the problem occurred, and the injectors were not opening every third tap ( this is the difficulty with intermittency) 

 

I tested the negative coil wire(disconnected from the coil post) for continuity to ECU Pin #1, and it read zero resistance. It was reading correct voltage to pin #1 when given power as well. Im confident the signal to pin #1 is fine. My next step is to try and ground the injectors from the ECU connection manually to see if that will fire the injectors. Im waiting for the problem to come back to test that...

Edited June 13, 2019 by stravi757

[stravi757]

I still havent found anything conclusive. I did remove/pull the pins from the connectors of the EFI Main Relay and the fusible links. They were a little corroded but not badly. They all tested fine prior. Since I cleaned them the car has started without issue. I will find out through time if it corrected the problem.

Edited June 14, 2019 by stravi757