Hi all. I guy I know is having a problem with his cossie. The car runs and drives perfectly, no idle issues, no hunting, boosting well, no missfiresmoking. When the car is up to temprature and you turn it off we loose spark! Won't start again until its cooled down a little.

Car is a 2wd saph. So what have we done so far? Replace crank and phase when at temperature with no luck. Pulled the engine harness and contiuity test every pin back to the ecu. All is good there! Strange thing is the pump doesn't prime when you key on either but pushes volts to the pump when you crank and runs perfectly? Relays have been changed still the same and a fuel pump rewire kit installed correctly.

Tried another ecu in the car and pump doesn't prime either.

Any ideas please coz I'm stumped. Security relay? When the loom is back in the car we will bridge the perminante and ignition feed to eliminate this.

Thanks in advance.

 

Water temp sensor to ecu, made this problem to my Sierra