TBI troubleshooting

[44th Miss Inf]

Working on an 88 R30 with tbi 454. Truck has sat up a while and I was asked to get it going again, so troubleshooting the tbi system.

So far only thing I have change is the oil switch for the fuel relay, as it was damaged. I know the passenger tank pump is bad, as I’ve jumped 12v to the test Port. Passenger pump won’t run, but hooked up a spare sending unit / pump and that pump runs.

I can hear the selector valve changing, but haven’t had time to check if I have power to the left tank.

Need to put my hands on my spare hot start module and ECM from an 88 7.4/400 truck I had.

It has a blown ECM B fuse, so I’m also checking for shorts and good grounds in the circuit. Once I get fuel sorted, I’ll work on the other bugs in the truck.

Been a while since I’ve worked on tbi systems, so having to reach into the unused files in my head (also have my service manual out)

Going to see what pumps I can pick up local, either the ep381 (96-97 Vortec) or ep377 (95 tbi) I’ve run both before on the tbi systems even though they do have higher pressures. The ep386 (stock pump) just never seemed to supply enough fuel for the 454.

Getting to old to be climbing under a truck or leaning over in an engine bay, lol