I have an 86 C4 that is giving me serious starting problems. Not getting any power to my fuel pump. Took fuel pump out tested it by connecting to 12v battery. Worked while on my work bench. Placed it back into the tank and car will not start. No fuel going to fuel rail and still no power at the wiring harness connecting to the fuel sending unit. I have cleaned the ground wires inside engine compartment, behind rear driver side tire, power antenna connection, and also passenger side compartment. Am I missing any other ground connections? Need help as my Vette has been sitting up for almost 6 months and I am ready to put it on the road this fall. HELP!!

 

Welcome to the forum.

There's a relay that cuts the power to the fuel pump if the oil pressure goes too low.

 

I have an 87 and it's the opposite problem. Fuel pump runs all the time. Tracked down to Oil Pressure Sensor. Seems if there's no oil pressure there's no fuel to keep it running. Trying to find correct part number as it was used on 1985-86-87. Has two prongs and is available all over as oil pressure switch with light. Youtube has a video where a guy shows you how it works. Mine draws down battery when shut off. Must be stuck. Good luck.

 

Welcome to the forum . Thanks for the info.