I am currently ready to break in my 406 sbc (carbureted) in my '87 IROC (used to be TPI), but of course there was an unexpected problem. I went to start the car and run it for 30 minutes, but as soon as the car ran for a couple seconds, the fuel pressure dropped to 0 and shortly after the car ran our of gas. The car has a full tank and the fuel pump does kick on and prime, but does not seem to stay on the entire time. I know the pump is supposed to stay on when there is oil pressure, which there is. I checked the wiring schematics for the fuel pump relay, the only difference from that to my car is instead of a light blue/ white wire, there is a tan/white wire. I was wondering if anyone could supply me with better wiring schematics or have any information on how to keep the pump running at the turn of the key. I tested the pump and checked the fuse, and both seem to be alright as well. Any help would be appreciated.

 

I'm guessing you removed the ECM. It used to run a relay to keep the pump running, and the oil pressure switch was a redundant path.

I don't have a schematic to offer you. Used to be one in a swap sticky, but it was rehosted and lost.

 

Actually, the ECM is still in place. The only wires I cut were for fuel injection and emission sensors. I used the same sending unit for the oil pressure and it shows on the tach. I don't know what the problem is.