Question about 1996 GMC Sonoma

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Fuel pump will not come on 1996 gmc sonoma 4.3

I have power at gray wire for 2 seconds at pump

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Well that is the correct action of the pump relay. The computer grounds the pump relay for a couple of seconds to prime the pump then the oil pressure switch provides power once the engine starts.
You should be able to jumper the relay and power the pump as much as you want to test the circuit.

Posted on Jan 04, 2013


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Posted on Jan 02, 2017

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SOURCE: where is the fuel shutoff switch on a 1996 gmc sonoma?

no fuel shut off switch on pickups that i know of possibly bad fuel pump find your red bypass wire at relay to test pump

Posted on Mar 29, 2009

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SOURCE: 1996 GMC Sonoma heater core

the dash has to come out

Posted on Sep 11, 2008

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SOURCE: Have 1996 GMC Sonoma 2.2L engine. Have just

i had the same problem with my 96 sonoma, just died anywhere at anytime, even happened to shop mechanics. They checked fuel and spark, there was none. Ended up putting a new computer on it and it has not happened again. The computer was not communicating with anything, just be sure that you get new comp. programmed to your vehicle. Had to send mine out and get done

Posted on May 13, 2009

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SOURCE: 1998 gmc 2500 sle 5.7 wont stay running

this is in fact the right answer check the oil guage in the truck it should read about 375.

Posted on Dec 15, 2009

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SOURCE: How to change a fuel pump in a 1996 Gmc Sonoma

drop the tank ... use a brass punch to loosen the ring ... to find/replace the pump.

the relay is operated by the computer ...

Check for volts on the outgoing side of the relay ...

check for signal on the input side

check the pressure regulartor ...

If you are still interested ... there is lots more to this. If you are getting weak knees ... remember after you drop the tank and remove the fuel pump ... you are stuck

Posted on May 02, 2010

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Fuel pump is not getting any power on 1996 gmc sonoma

And the question is?

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1 Answer

Do the fuel pumps have a high failure rate for gmc sonoma 4.3 1996? it was running great last nite and this a.m. nothing, no noise at pump when turn key, but 8-9 volts on the small square three wire plug...

You should have 12v at that wire.Definitely would check for corroded or loose wiring especially on the ground that runs to the frame on this you are for sure losing enough voltage to cause the pump not to work. If possible try running a jumper wire from the battery to the pump power wire which I think is purple or red and see if your pump will activate.

Dec 28, 2010 | 1996 GMC Sonoma

1 Answer

I have a 97 gmc sonoma and replaced the fuel pump and have no power now to pump. I found the test wire on truck and ran a test through the relay and worked, but pump still does not work. I have changed out...

It really helps if you post which engine you have and the 8th VIN digit. I ASSUME its a V6??? You should have 12 volts for 2 seconds on the gray wire (at the pump) when you turn the key on, If not, check the ECM/BATT fuse #9 20 amps, in the dash fuse panel. IF you do have power, then the relay is working and that is ok, If it does have power to the gray wire, then shuts off after 2 seconds thats normal. NOW while its running the fuel pump gets power THROUGH the OIL PRESSURE SWITCH. So get it running with your test wire, then disconnect your test wire. If it stalls out, then the oil pressure switch is either bad or disconnected.

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you say you replaced the fuse, but does the fuse have power? the gray wire at pump should have power when cranking, or for 2 seconds when turning key on. At fuel pump relay, put power onto gray wire, the pump should run if the wiring is good. if it doenst run then ck for power at fuse while power is on gray wire.

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1 Answer

Where is the fuel shutoff switch on a 1996 gmc sonoma?

no fuel shut off switch on pickups that i know of possibly bad fuel pump find your red bypass wire at relay to test pump

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