QuickShift

iTrader: (4)

Ok, having a really weird issue. Got my 67 camaro with LS2 swap done a few months back and has been running perfect. Used a PSI conversions harness and ECM. One day I turned the key, fuel pump primed, but no start. Then when I turned the key again, no fuel pump at all. Every once in a while the car will prime, but not start, and then next time I turn the key the pump is not working again. Also noticed the fans are coming on while cranking over. Tried new relays, checked fuses...no luck. When I hardwire the pump it stays on so it's not the pump. Any ideas please... it's driving me crazy.

stevieturbo

Any fault codes ?

QuickShift

iTrader: (4)

After several tries I finally got the engine scanner to connect and pull a P1336 crank sensor relearn code. Honestly thinking it could be the ECM...

Compsystems

sounds like a short somewhere.

The fan run signal is a ground trigger, if the wire rubbed somewhere it would ground out and run the fans.

The fuel pump is a 12v+ signal and if shorted 0 volts would get to the fuel pump relay.


Can you check live data on your scanner? During the problem what is your coolant temp? I think the PCM can shut off the motor and run the fans if it thinks its overheating.

stevieturbo

Fans can often come on when the ecu is in a fault mode, or unhappy with something.

View the data, see what the ecu is saying.

QuickShift

iTrader: (4)

Thanks everyone for chiming in. Called up PSI conversions and the tech told me to check the ground on the back of the cylinder head...bingo. Bolt was just a little loose.