924Board.org

[peterk]

I have a 1987 924S that's not getting any fuel pressure.

Issues seems to be that I have no power at the fuel pump.

Confirmed that the fuel pump relay is good (bench tested using a bench power supply, and the 2 internal relays click).

Just in case I replaced the relay and still no power.

I also jumped the 12V at the relay but the pump didn't seem to be working so I initialy thought it was a bad fuel pump.

I removed the fuel pump and tested with 12V; seems to be working fine.

Fuse isn't blown

The odd thing is that I'm seeing 5 ohms resistance from the fuel pump power line to ground (with both the fuse, relay and fuel pump removed). This should be an open circuit right?

My best guess is that there is a short at the wire junction between the fuse and the pump terminal.

I found this electrical schematic on another thread here, so the only thing between the relay and fuel pump is the T1 bullet connector


Any suggestions on this? Does anyone know the location of this bullet connector?

[peterk]

After testing the fuel pump back in the car, the pump starts and stops when under load. So it definitely needs a new fuel pump. I'm still concerned that there isn't an open circuit on the 12V line to the fuel pump.

New fuel pump should be in here end of the week, so I'll post an updat then. But if anyone has any suggestions on my initial question I would appreciate them!

[peterk]

Quick update for anyone who might find it helpful in the future.

Installed new fuel pump and car started using the jumpers in place of the relay. Removed the jumpers, installed original relay and car starts up fine.

So it looks like the few ohms resistance to ground on the 12V supply to the fuel pump isn't an issue (or at least doesn't appear to be an issue).

So in my case it was just a bad fuel pump.

Fuel pump is located under the car, behind/beside the rear passenger wheel. Jack up the car on the right side and it's easily accessible. I purchased a new pump on eBay for $25.

[holcopa123]

I'm not an expert on this. If the fly wheel sensors aren't picking up the engine moving then the computer won't power the fuel pump, close the circuit. This is to prevent the fuel pump from pumping if in an accident, don't want fuel all over the place if upside down in a fire.

Phil
1987 924S