2000 S10 fuel pump problem


flame829
05-15-2007, 07:42 PM
2000 S-10, 2.2L. Fuel pump stopped pumping. Got a new fuel pump that bench tests okay, but won't work in pickup - old pump bench tests bad so thought that just needed changed. Checked fuses and relays and all are okay. Wondering if anyone has a wiring diagram for a 2000 (haynes only shows 95 and it is different than my 2000) or knows if the oil pressure switch that is referenced in haynes can be reset or perhaps just goes bad or just how to test it - haynes said that can shut down your fuel system. Haynes wiring show a three wire oil pressure switch, but mine is only one terminal. I have followed wires and see nothing burnt or broken. Could it be a problem with the pcm or ecm? Didn't drive truck for several months and have taken out old gas and added new gas. Truck is very low miles - under 40,000. I saw threads from 2005 from burlswift, but didn't find what was actually determined to be wrong.:frown:

Also, old pump seized - didn't just stop pumping - I think it may have blown something - but not a fuse or relay - would that be possible? This has us baffled.

Additional info - we can hear a click in the relay when we turn the ignition key on and then a few seconds later we hear another click and it seems that something is shutting off or stopping power to the pump relay and thus to the pump.

MT-2500
05-16-2007, 11:21 AM
First thing do not bench test a fuel pump.
You can burn it up running dry.
Now flip key on can you hear the fuel pump run for the key on prime cycle 2-3 seconds?
Gray fuel pump wire from relay should have 12 volts threw the fuel pump prime cycle.
Can you hear fuel pump run or have fuel pressure on engine cranking?
Is Fuse ECMB hot on both sides?

At fuel pump relay does orange 12 volt feed have power key on?
If so check for 12 volts on the gray fuel pump feed on key on fuel pump prime cycle.
To test fuel pump jumper a fused 12 volt jumper to the gray wire or fuel pump prime connector and see if fuel pump runs.

Forget the oil pressure switch deal in Haynes manual.

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