Question about 1998 GMC Sierra

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1996 GMC K1500 Pickup Starting Problem

This truck has an OBDII computer on board. When i turn the key to the run position the fuel pump used to come on a build pressure in the line for a few seconds. It has stopped doing this. When i turn the key to the start position it turns over and grinds and grinds, no fuel. I have replaced the fuel pump, oil pressure/fuel pressure switch, and checked the fuel pump relay. I have also scanned the onboard computer and it has no trouble codes. Any help would be appreciated. Thanks in advance for anyones help. 98 gmc 5.7 fuel gauge crazy works wen in gear, trouble starting ocasionaly have to pour fuel in t.b., drive on highway @ speed and once back at idle will die, can feel power loss and regain in 2-3 min incrimints on highway ???

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I would try a fuel filter first. the fuel gauge going crazy is most likely the sender they go bad and eventually stop working. the bummer is you have to replace the fuel module. these aftermarket are about 200 bucks. the module comes with the pump and sender which is the next part you want to look at. gm has some issues with the harness to the fuel pump externaly. it actualy will melt and start to lose conection. i would check this by visualy inspecting the plug on top of the tank. unplug it and take a look. if it is at all disscolored replace the pump (module). the new pump comes with a replacement harness (make sure its in the box)hope this helps and good luck

Posted on Feb 04, 2009


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no you will not have fuel pressure untill the engine is running

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Sounds to me like either your pressure regulator is bad or you have a loose fitting somewhere in the fuel line from the fuel pump to the engine. When you turn your key to the on position, you should hear the whine of the fuel pump until it builds pressure. When you shut the truck off the pressure regulator should retain the pressure for a certain amount of time but if it don't close then air is allowed into the fuel line and the fuel drains down to fuel line away from the engine. Next time you try and start the truck after it has sat for a while try turning the key on until you hear the fuel pump whine shut off, then repeat it 3-5 times and then try to start it. Basically that is running the pump enough to get the fuel back up to the injectors. Check for loose fittings in the fuel line, or cracks in the fuel line and if all that is fine then replace the regulator.

Hope that helps

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