That's what I was figuring, I could have swore I heard it kick on a couple times since it has been dead, but I could have been hearing things. The onstar speaker right beside my head sometimes makes some funny noises. I guess the tank is going to have to be dropped. Does anybody have any tips or precautions to share? Only thing I usually worry about is breaking fuel lines.

 

You can turn the fuel pump on and off using the bidirectional controls in the HPTuners scanner. That might help you diagnose your troubles.

 

I had no idea you can do that on there, I'll have to check that out after work. Thanks

 

Good luck with dropping the tank. I've only pulled the pumps on trucks not Hoe's so I don't have any useful suggestions other than make sure the filler hose is also disconnected from the body.

 

I've done that before, get ahead of myself and the filler hose is still hooked. I hate projects like these. I'd rather spend the time and money on a performance upgrade for it.

 

Just for the hell of it, I dragged the tahoe to a level spot on the driveway and put a few gallons of gas in it. At first it didn't do anything different, but then all of a sudden it started up and was running rough. Seemed like it was going to stall, so I tried reving it up and it would only rev to 2000 rpms and would die out. I'm thinking a weak fuel pump, just wondering what you guys think. Thanks for the help. Tim

 

hey guys, I dropped the tank and took out the fuel pump. I tried checking the wire harness to see if I got power. It had a reading a couple of times, but not very consistant. Also, when I took the fuel pump out, I bench tested it and wasn't getting anything. I was curious to know what each of these wires for the harness are supposed to be and when and how many volts are supposed to be traveling thru them. If anybody knows, I'd appreciate the input. There is a square 4 wire plug that has a black, purple, gray, and an orange with a black stripe. There is also a 3 wire plug that has black, green, and white. When I took the pump out, I could see where the wires go on the 4 wire plug, but I can't see a thing when it comes to the 3 wire plug. I'm almost certain that the 4 wire plug powers the pump with 2 wires and gets the fuel gauge level on the other 2. I have no clue what the 3 wire plug does. Thanks for your help. Tim

 

The ppl wire is the signal for the fuel level gauge. Black is ground. Gray is the supply voltage for the pump, which should be ~ +12-14vdc, and the orange/blk is the reference signal.

 

Thanks for the help. I assume the fuel level gauge wire and the reference signal are going to have varying voltages. What is the other sensor on the pump?

 

Pressure sensor if I'm not mistaken.