A&Q about 350Z
Q:
I'm after some ideas, and to see if anyone else has had this problem.
So far this year, my '96 MK3 (AGG) Gti has refused to start 3 times. Twice it has eventually started, and once it started after I left it overnight.
The last time it happened, I managed to get VAG-COM on it. While it would not start, the software refused to connect to the ECU; but it would connect as soon as the car was able to start. No faults were stored (typically).
I feel that it may be the Golf's built-in immobiliser, either the key, pickup coil or the immobiliser. I don't believe it to be the alarm's immobiliser as that cuts off the coil, and would not affect the ECU. I've not even bothered checking for a spark as it's pointless if the ECU is unresponsive when it's happening (not that I get a chance to check).
It's a ***** to diagnose as I can't trace it while it's working, and I can't get it to reproduce the fault. It all means that I can't trust the car.
A:
Change the ECU relay first...