'93 VR V6 will not start!

[knuckles84]

Hey all

Ok, at the moment my car is stranded on the side of the road and I can't get back to it until the end of the week (and no Towy would tow it on a sunday!) but I just want to brainstorm for some ideas...

So, exactly one week ago I drove about 40 mins to get to a wedding ceremony, the car ran perfectly the whole trip. I parked it and when I came back after the ceremony about an hour and a half later the car wouldn't start. It would fire and turn over for a second then stop. Fuel? right? So as it was a fair ways from home I got it towed to a nearby mechanic and he was convinced it was the fuel pump... sounded reasonable to me so he went ahead and replaced it. Problem solved.

I drove the car to work and back on 3 occasions with no problems (each time leaving the car for at least 10 hours before restarting). Then, yesterday I drove up the road to a mates house and turned her off for about an hour before restarting... guess what? same problem as before - car starts and runs for a few seconds then dies.

Now all I had with me was my trusty leatherman and a paperclip so I checked:
*for fuel at the rail - seemed to have plenty of flow
*cooling the Crank angle sensor with water - no change
*the spare key, in case of immobiliser issues - no change
*checked fault codes - code 12: no problem
*Operation/condition of fuel pump and Efi relays/fuses - all ok
*Plugs to Ecu/map/airflow/crank ang sens/oil pressure sens/ - all appear ok
*Spark (JUST IN CASE) - all good

Now it seems to either fire and run for a second or just turn over on the starter with nothing at all in complete random orders.

I'm certain its a fuel issue... I can here the pump working and it has flow, although i havent been able to hook up a pressure gauge just yet. Or possibly a dodgy sensor like Crank angle or coolant temp preventing it from starting???

I have never worked on commodores so I'm not 100% on all the ins and outs of the electrics so if anyone has anyone got any ideas Id really appreciate it
Thanks in advance

[hako]

Check the oil pressure switch - it controls power to the fuel pump once the engine starts. It's designed so if you have a head-on and engine stops then power to fuel pump is stopped by oil pressure switch. (no fuel = no fire). When you turn key on initially the ECU runs the pump for a second or two to prime the fuel rails...car starts and oil pressure rises closing contact in oil pressure switch supplying power to pump.

[-=ApheX=-]

check your battery earth, this is something commonly overlooked as a typical fault, the earth lead comes of the negitive terminal on your battery to the drives side of the engine bay, check and re check that it's connected with out errosion!
I would also check the plastic insulator on the back of your alternator, as time goes on these will crack and decay because of the heat, if this is the case replace immediatly as there would appear to be a short causing your car to fail and not start!
reasons i am putting this to an electrical fault is that you don't appear to have any error's logged, but that is to say the error's are a generalistion of problems, but that being said if this is an earthing problem, or an electrical issue there'll be no error logged with these components!
you can pick up insulators for your alternator from any auto electrician, these range between $5 to $10 depending... Also i should mention make sure there's good connectivity with your battery terminals also!
Good luck mate