2000 gmc jimmy shut off while driving, replaced fuel pump relay, did not help. checked fuel pump and filter, both seem okay. after disconnecting and reconnecting fuel filter, vehicle started and ran very rough for a few seconds then shut off again, won't restart.

This might apply .. but it for a 1999 Jimmy:
Electronic Fuel Pump Computer Problem6 Cyl Four Wheel Drive

Your symptoms could also be do to other issues ... not just the fuel pump relay. Read the embedded link within the 2carpros response.

Good luck with your troubleshooting

you say fuel pressure is good, but what is it? what is the fuel pressure when it stalls out? Spec is 60-66 psi and it wont run if its 55 psi. the fuel pump relay should be good if the pump runs. Make sure the ground for the pump is good , G402 should be on left frame rail. you may have had it off to replace the pump? maybe? it may be time to stop guessing and have a repair shop diagnose it for you. You sure have replaced a lot of good parts.

Fuel pump relay inside the glove box is kaputz? http://www.ehow.com/how_5486354_replace-jimmy-fuel-pump-relay.html

the (airtext)brand of pump seem to have this problem ...install a( delphi)brand should fix problem...

okay if you have spark sounds like fuel delivery... if pump is new then check the fuel filter..... if filter is good check to see if there is a secondary fuel pump bolted to the driver side frame rail.... if everything checks out fine find the inertia switch and reset it it is possible it can trip.... it is a fuel shut off switch designed to trip and shut off fuel in case of an accident but malfunctions do sometimes occure with them... hope this helps

If you have replaced the fuel pump and filter I would still check the pump pressure when it wants to die. Check for any trouble codes in the system also.

Check fuel pressure at schrader valve on fuel rail while key on and engine not running. Spec is 55 to 61 PSI. If it is lower than 55 PSI, replace fuel pump and fuel filter.

How about your fuel filter,????

yea you have no fuel and sound like a bad harness and the gm's are know for there fuel pump harness's! did you change it when you changed the pump? there is a lose connection somewhere in the fuel delivery system and it's pretty simply! i would check the fuel pump relay on the left hand side of the engine compartment and maybe even put power to the pump at the relay position "b" on the fuel pump relay harness and there should be a one pin connector to put power to also connected to the same position on the relay "b" the wire should be tan and white! good luck

Check your Fuel Pump Relay and Fuel Pump + Change the Fuel Filter. Should get you going again. Please Rate My Response! Thanks!