Fuel Pump Problems

I have a 1998 GMC Sierra 1/2ton with a 4.3L which has 220,000kms. Yesterday i went to start my truck and it wouldnt start. I noticed that when i turned the key on i couldnt hear the fuel pump run which i always could before since the fuel pump has always been loud on any gm truck i have ever seen. i took the box off to get at the pump and i wiggled the wires and it started right up first try. then it wouldnt start again. we cant seam to get any power to the fuel pump on the test light. we can however get power to the fuel gague plug. i am stumped and would appreacheate any help. thanks.

sounds like a broken wire must be pinch or kinked somewhere where you wiggled the wire. gonna need to drop so you can see whats going on

There is a known problem with the connectors getting burned inside the pins. Unplug the connector and take a close look inside. The TSB with pictures from GM says to use a newer type of plug.
I had a friend's truck with this problem in the Aridzona desert.
Also NAPA parts has a poster picture of a bad plug on the wall here in town.
You can put a 12volt jumper to the red pigtail behind the relay/fuse box, just below the brake master cylinder to make the pump run continously thus bypassing the computer and relay.
Bob B

Thanks for the advice.

Hi, just one more question. i am going to test the fuel pump by placing a hot wire on to the pins and see if i can get any power to the pump. on my fuel pump there are two connectors, one has 3 prongs and one has 4, i think the one with 3 prongs is for the fuel gague but can anyone confirm this for me?also i was told that there was some type of regulator behind the distributor? i think the guy was talking about an older model gm that has the fuel pump and sending unit as seperate units where as mine is all one component dose anyone have any knowledge on this topic? Thanks.

Hi, just one more question. i am going to test the fuel pump by placing a hot wire on to the pins and see if i can get any power to the pump. on my fuel pump there are two connectors, one has 3 prongs and one has 4, i think the one with 3 prongs is for the fuel gague but can anyone confirm this for me?also i was told that there was some type of regulator behind the distributor? i think the guy was talking about an older model gm that has the fuel pump and sending unit as seperate units where as mine is all one component dose anyone have any knowledge on this topic? Thanks.
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I wouldn't mess around back there yet! You might damage the sender for the gauge.
Just hook the 12volts to the red jumper below the brake master, behind the relay box.
This eliminates every thing except the wire and connector.

THanks for the advice, we looked for the jumper but couldnt find it. But we placed power direcetly to the fuel pump via a wire from the battery and the pump started. the strange thing is that after we did that the pump kept working. i cant understand it, we didnt really do anything to fix the problem. we are going to pull the pump out next and check to make sure that it is not clogged or something. Did anyone ever hear of a pump getting stuck?

THanks for the advice, we looked for the jumper but couldnt find it. But we placed power direcetly to the fuel pump via a wire from the battery and the pump started. the strange thing is that after we did that the pump kept working. i cant understand it, we didnt really do anything to fix the problem. we are going to pull the pump out next and check to make sure that it is not clogged or something. Did anyone ever hear of a pump getting stuck?
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Did you check the plug sockets real close? GM knows about the problem and recommends replacing the whole plug with a newer type.
My friends 97 Tahoe had a burned contact in the plug on top of the tank and when it first started to act up he would hit the bottom of the tank which would fix it temporarily. Eventually he had the pump replaced for around $500 and it failed in the middle of Nevada (hitting it didn't help this time). So it was replaced again there. Then it failed again in the Arizona desert. This time we dropped the tank and the first thing I saw was the burned contact. We replaced the contact with one from the hood light socket. It is finally fixed.
Neither shop looked at the pins even though it has become a common known problem.
Bob B