:help2: WEll, I got the cursed:mad: Suburban running yesterday with a REMAN pump. Ran for about 150 miles today and went to pass and when I accelerated there was a hesitation when I stomped on it. I made it home and parked it. Came out couple hours later to start and it started roughly. Idles but not good and as soon as you push the accelerator it runs real bad. I replaced the P MD just out of curiosity and no change. I hear no noise from the lift pump. Can a bad supply pump cause it to run like crap-:t? It was dark and wind blowing on the Alberta prarie so I did not get to do a voltage test on pump. Before this happened I could hear the supply pump "clicking"... now I cannot hear it when oil pressure builds...

:help2: WEll, I got the cursed:mad: Suburban running yesterday with a REMAN pump. Ran for about 150 miles today and went to pass and when I accelerated there was a hesitation when I stomped on it. I made it home and parked it. Came out couple hours later to start and it started roughly. Idles but not good and as soon as you push the accelerator it runs real bad. I replaced the P MD just out of curiosity and no change. I hear no noise from the lift pump. Can a bad supply pump cause it to run like crap-:t? It was dark and wind blowing on the Alberta prarie so I did not get to do a voltage test on pump. Before this happened I could hear the supply pump "clicking"... now I cannot hear it when oil pressure builds...

Sounds like you need to run the whole gammit of tests for checking the lift pump system: OPS check (voltage at pump while running) or replacement and a lift pump pressure test.. See the FAQs via the link in my signature for more info...

Snip the wire going to the OPS that supplies power to the lift pump, ditch the fuel pump relay in the under-hood fuse box, stick an add-a-circuit in a hot-with-ignition slot, and run the hot wire to pin hole 87 of the fuel pump relay.

You won't have to worry about the OPS taking a dump ever again.

Jump your lift pump first to make sure it's working properly.

Tested power to the lift pump - I get about half a second of 12V then nothing. I assume it is the OPS. Can you explain the procedure above in more detail. Sorry but I dont understand a couple of the terms:

"stick an add-a-circuit in a hot-with-ignition slot, and run the hot wire to pin hole 87 of the fuel pump relay."


Am I supposed to remove the relay completely? What is an "Add a circuit"? Sorry to sound so dumb but I am when it comes to this stuff.

Tap into a circuit like from the fuse panel thats hot when the key is ON. Use that wire to run a relay to feed power to the orange wire on the supply pump.

Well I screwed up again!! I took the pump relay out and jumpered pin 87 to one of the other pins in the fuse block and wamo I blew a fuse some where. I have no glow plug relay and no start. Anyone know whck fuse I would have blown? It would have been the pin 87 in the block...

Check the ECM fuses in the fuse panel under the hood.

I replaced the ECM fuse and got my glow plug light going but I cannot get it to start. The lift pump is operational and fuel is coming out at fuel filter with good pressure. Cranks and sounds like it wants to go but will not kick in. Are there other fuses that may be related to my screw up above?

Got her running again. May have been air in the system. Cranked it for a while and finally got it to run.

Thanks for the help.