Fuel Or Electrical?

[bobstocker]

I have a 1998 GMC sierra p/u that has developed a problem with the engine cutting out like it is not getting fuel. The problem is prominent when on bumpy , off roads, and only occasionally on highway. The truck starts and idles fine. When being bumped around , the engine will miss or act like it is not getting fuel , not so much like a backfire, but almost like the electrical of the fuel pump gets cut off. I have replaced plugs , fuel filter and fuel pump less than 15000 miles ago. I am wondering if the electrical plug to the fuel pump has intermitent connection or is there some fuel pump pressure sensor on this vehicle? I was going to check the obvious such as plugged fuel filter and the pump eletrical connection.

The fuel cutoff gets worse the more bumpy and/or engine work load when it need fuel most. Suggestions for other things to check? It has 108000 miles on it and otherwise runs good.

[C6Racer]

Since it does this mostly when you're driving on bumpy terrain I would suspect an electrical problem. Wires may be getting bumped around. You might be able to get under your truck and reach over the top of the fuel tank to wiggle the fuel pump connector to make sure it's installed firmly. You might also want to check the ground cable and the fuel tank ground strap.

I forgot to tighten down the ground bolt last time I replaced my fuel pump and was having similar problems.

If you still have problems, my next move would be to test fuel pressure and the pressure regulator.

Good luck!

[pennzoil29]

Since it does this mostly when you're driving on bumpy terrain I would suspect an electrical problem. Wires may be getting bumped around. You might be able to get under your truck and reach over the top of the fuel tank to wiggle the fuel pump connector to make sure it's installed firmly. You might also want to check the ground cable and the fuel tank ground strap.

I forgot to tighten down the ground bolt last time I replaced my fuel pump and was having similar problems.

If you still have problems, my next move would be to test fuel pressure and the pressure regulator.

Good luck!

 

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