VX commodore turns over but won't fire

[ulath]

Hi, I have a 2001 vx commodore. I can drive the car everyday for weeks on end and it doesnt miss a beat. Though sometimes it starts, I drive 20 feet and it stops then it turns over but wont fire. Sometimes i can come back an hour later it will start or the next day, and it will fire and seem to be running fine when i run it at temperature i know it wont fail me. I had a mechanic put a diagnostic unit and it said crank angle sensor fault. So i had the crank angle senor, cam sensor and the Harmonic Balancer replaced ( mine was cracked all the way around) and the battery is brand new also. When he tried to start it, again it cranked over but wouldnt fire. The diagnostic readout came back as an ignition fault. So i didnt try and restart the car, got an auto electrician asked him to put the computer on it to see the code and what does he do? he starts the car clearing the fault codes. So again , i drove it for a week and it performed flawlessly. The other day, I started it, ran for 30 sec then it stopped. Again it turns over but wont fire. Problem is that it always fires and runs fine when i have the mechanic out. The Auto electrician discounted the posibility of immobilser and key as the fault. So im lost atm to what the problem is. Any ideas? Thanks

 

[Elkins2013]

If u leave ur key in the "on" position, with ur dash illuminated for 10-15 mins and try start will it fire over then??

Im having a similar sounding problem, however mine always cranks but never fires unless ignition is left on for 10-15 mins