81 c30.....5.3

[low82c10]

Long story short, I had the 5.3 In a c10 pickup and it ran perfect (stand alone harness 3 wire hook up). I got a C30 truck and put the engine in that, I went to fire it up and it wouldn't start. I grounded the wire but power steering pump and it fired up like a champ.



After about 6 start ups, it was running and all of a sudden it died, now on switched 12V it doesn't kick the fuel pump on for a few seconds nor do I have throttle response on switched 12V. I used to be able to push the gas on switched 12V and the throttle would respond, now I got my response or no fuel pump.


I directly hook up the fuel pump and it works. I've checked all my grounds and they are to Bare metal. With switched 12V both number 1 pins are grounded.

Harness is drive by wire, I tried unplugging the throttle body and the pedal and no luck. Also I swapped the fuel pump relay with a fan relay, still no luck,


Any idea where I should look next ? Thanks you.