Throttle body injection problem
1987 Chevy 350, TBI runs but quits after 15 to 20 secs, must turn back ignition switch (key) and it will start again with same results. Something is cutting the power to the fuel pump after 15-20 secs. I put 12V to tan/white wire to the fuel pump, and the pump runs, van will keep running with 12V there – not the fuel pump.
Replaced fuel pump relay, and no change. Thinking about the oil pressure switch, also part of the fuel pump circuit.
Is there a way to diagnose this problem? I don’t want to randomly change out sensors and modules if they’re not broken.
Any help would be appreciated.