1998 Tahoe fuel problems

[chevytrucks79]

Truck has 130k miles. My dad gave it to me because his mechanic couldn't keep it from shutting off on him. Somewhere on this site I saw that the hoses were a problem on the fuel sender, so I put a new one in last summer and haven't had any problems until this month. I am not getting fuel up to the engine. Using a schematic I found online I was able to confirm I had voltage leaving the relay box for the pump, so I thought maybe the connector had got loose, but when I dropped the tank I found everything was still hooked up. I had my wife try to start it so I could observe the pump while it was out of the tank, and the truck started right up. I thought maybe it was just a fluke occurrence and put it all back together. Well two weeks later it is dead in the driveway again. I dropped the tank and just like before the truck starts with the pump out of the tank. I'm pretty frustrated with this thing now. The sender I got was a Bosch, but looking through old posts it appears it might not of been a good choice. They only other factor that may be playing a role in this mystery is I am jacking the back of the truck up pretty high as to be able to get the tank out. Would that slope be doing anything to allow it to run? No, I have not changed the fuel filter, the dealer replaced it last summer and the fittings on the front connector are stripped out. (they wanted $900 to fix it)I have to redo some of the fuel lines to fix that. I am open to suggestions there also.

[speedygonzales]

Did you ever actually confirm the fuel pressure(or lack there of) when you are having the problem? Knowing what the pressures are is important to find out several things. Like restricted return line, plugged filters, bad regulators and leaking injectors.

Many pumps will fail but if they are "bumped" will begin to work. They get spots in their rotation that will stop functioning. Not sure if it's bad spots where the brushes touch or not. But these pumps will begin to pump again. The first thing we do with a vehicle that has no pressure is tap on the bottom of the tank while someone cranks it over. In my case, it got me from a shopping mall to the dealer to get a pump when I got stuck. I've seen people drive around with a cut off broom stick. When they can't get the vehicle to start, they get the stick and beat on the bottom of the fuel tank. Get back in and start the car.

By you messing with the pump, you may be doing the same thing. If you want to test it, with the system assembled. The next time you can't get it to start, have someone crank the engine while you bang on the bottom of the fuel tank with something like a rubber mallet.

Just FYI. There are certain items in the vehicle that you never EVER get anything other than OEM. The fuel pump is one of them. Fortunately you can get AC Delco items at places like NAPA and Summit Racing.

Good luck and let us know what you find.

[BigBlocksRule]

Hit a salvage yard for your stripped out fuel line - there's not enough length to re-do the end. Tried it once, not worth the trouble.
If it's a 2-door, jacking it up will definitely make a difference if there's not much in the tank - mine dies when I hit the brakes when fuel level is low, starts right back up when the fuel stops sloshing. Can't say for a 4-door, never messed with one much.
Double check all connections, pay particular attention to ground. I'd consider removing it from the frame and cleaning everything up and reattaching it.

[chevytrucks79]

Yes I did verify there was no fuel coming up at the fuel pressure port. I also tried beating on the tank before dropping the tank again. I'll get a pump from napa and try again. Ill check the junk yard for a fuel line also. Thanks