Mikes91
Full Access Member
My wife's '98 GMC 3500 won't start. We tested the fuel pump and came back with about 12 PSI. Dropped tank and replaced fuel pump. Turns out the pump should be for a '97 truck because the truck is a pre-June build and uses the '97 pump.
Now have 15 PSI with the new pump, but the truck still will not start. It will start and run if gasoline is put in the intake. She has a Vortec 350 in the truck.
I think, but am NOT sure, that the '97 trucks with this fuel pump needed 51-55 PSI to run. We are getting 11 volts at the pump, which is full battery power with the key "on" and daytime running lights on. I think that pretty much rules out an electrical issue... 1 volt won't make that big a difference in pump pressure.
Any ideas? We have spark. Timing chain shouldn't be an issue... I think the issue is why we're not getting 51+ PSI...
Thanks,
Mike
Now have 15 PSI with the new pump, but the truck still will not start. It will start and run if gasoline is put in the intake. She has a Vortec 350 in the truck.
I think, but am NOT sure, that the '97 trucks with this fuel pump needed 51-55 PSI to run. We are getting 11 volts at the pump, which is full battery power with the key "on" and daytime running lights on. I think that pretty much rules out an electrical issue... 1 volt won't make that big a difference in pump pressure.
Any ideas? We have spark. Timing chain shouldn't be an issue... I think the issue is why we're not getting 51+ PSI...
Thanks,
Mike
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