Gas Gauge / Fuel Pump Issue

I have a 99 Blazer LS w/ 73,000 mi. I have been having a problem with my gas gauge for the past six months where the needle gets stuck at a half a tank. The weird thing is that when I start the truck, the gauge initially reads that actual fuel level and slowly moves to a half tank if the actual level is below a half tank. If the fuel level is above half, everything appears to work fine. Also, after driving and putting the truck into park, the needle sometimes flickers back and forth. Does anyone have any ideas on what is causing this problem?

Also, about a month ago, I started to notice a high pitched whining sound while I am driving. It sounds like the fuel pump when it is being primed during start or shut off. The weird thing here is that this sound only occurs when the tank approaches the half way mark. When I fill the tank up, the sound goes away. My first action is to replace the fuel filter since it has never been replaced. But, I wanted to see if anyone else had any ideas.

If I do need to replace the fuel pump to resolve one or both of these issues, what is the difficulty level? I was quoted by the dealer $900-$1000 and really do not want to pay that much if I can do it myself.

Thanks in advance for any advise.

Have you ever replaced the fuel filter, if not do so.

Also, sounds like the rheostat in your sending unit is defective.

I have a 97 and it does the same thing, one minute it's at half a tank the next it is full, but it is never less then half.

BlazerLT - axe mentioned several problems, which one of those is caused by the rheostat?

The rheostat is what measures the fuel level.

It can become defective and stick.

Only fix really is to replace the sending unit in most cases.

Just ordered a sending unit for my 94,dealer 348.00,auto zone 179.00.Thought you might want to know

Thanks for the information.

I have a 2000 Blazer LS with the same problem as Axendo had. Except mine also has another problem. After idling for several minutes, the engine shuts down when accelerating. Any ideas?

with the fuel gauge....Is the sending unit hard to install?

with the fuel gauge....Is the sending unit hard to install?

A very easy installation, just remove the ring that holds the pump assemby in the tank. The sending unit is part of the pump assembly.
The hard part is getting the tank off.