does the gauge stay full even with the car turned off?..

If the gauge goes down with the car turned off you could have a short or a bad sender.

unplug the fuel pump/sender connector (under the car by the fuel tank. the gauge should go down with the car turned on). If not you have a short in the sender wire. If it does go down then you might have a bad sender..

 

when the car is off, its all the way down, when i turn it on, it goes all the way up. so im definetly going to do that tomorrow. thanks for the advice, CHEVY CREW STICKING TOGETHER!!.

 

Mine was stuck on full for a while (a while back) and it fixed it's self. I kept some bins with crap in the trunk and I must've hit a pot hole (or a few) and the "Thump" knocked the float free

. That's my story and I'm sticking with it.

 

Hopefully Dark-Saint has the solution?
Try banging on bottom of gas tank with a rubber mallet. Just might be a sticking Float?

 

My 91 was doing this about a month ago. I started logging my mileage with my trip so every 175 i'd fill up and reset my trip. After a while it fixed itself. I was making a big deal out of it but just decided to ride with it and maybe the force of me stopping, or going over a bump fixed it?

 

My harness shorted out and burned up my reostat (in-tank sending unit). Dal charges like $260 for a new one. Drop your tank and take a look, It's pretty easy. You can also purchase a universal in-tank harness at Napa for like $8 (just incase you need one).

 

i had the same problem in my 91, i just went to pepboys n got the fuel gauge cleaner, yes they actually make it, after about 10 miles with it it actually fixed itself, n the chevy dealership was tellin me my sensor was bad n needed a new tank n lines n everythin for like 600$, swindlers

 

what does this fuel gauge cleaner do how does it work? I have the same prob with my caprice right now and i am trying to fix it its a PITA when you dont know how much gas is in your tank!

 

My fuel gauge in the 93 is doing the same thing. When I first bought it the gauge stayed pegged out past were true full actually was. I put a can of Sea Foam fuel system cleaner in with a tank of gas to see if that would help clean the sender.

A couple of times since the needle has fell down to the red and the low fuel light comes on. When I put any amount of gas in the tank, the needle pegs out to past full again.

I filled it up for the trip to St.Louis and reset the trip so I could check my mpg later. I noticed after a while that the trip only showed 10 miles when I knew I had gone about 50-60 miles. On the way home I notice the trip was running backwards decreasing in mileage as I drove. The main odometer seemed to be working fine and was matching up with the mile markers on the high way. If a couple of more cans of Sea Foam doesn't clear it up, then I guess I'm dropping the tank. There probably a ton of rust above the tank that needs to be treated anyway.

 

Yea, I had the same problem I just replaced the unit in the tank, did cost me that much because I work for a Lexus dealer ship in Maryland, labor you can do it yourself, It will take just you and a friend to drop the tank, make sure you don't have any gas, it will make your job easy.. should take about and hour or hour in a half, depending on if you have the right tools (fuel line tools)... Good luck