Vital...I saw this on my 00 pickup. Chevy had a bulletin on the fuel sender in the tank. It would stay pegged and even while driving it would sometimes go to zero..and back...and OMG...talk about drive ya nuts.

When it does this...try putting the car into neutral. Our cars like my truck have programming or something built in so that the gauges won't move "too quickly" when you stop and start moving. I found that if I was cruising down the highway with the truck and the gauge was pegged in either direction I could let off gas..slider into neutral and the gauge would move to where it should have been.

What you are describing sounds like a sender.

I will try that...thanks for the tip!

I was told it was the sender, too. I'm just trying to get some more life out of that pump since the sender is integrated. Dealer wants $900 to drop the tank and change the pump. Local shop wants $700. I'll be doing it myself...

Mike, I can email you some instructions but I don't see how they are correct for your setup. I verified that my 97 sender is 40-250 ohms but the instructions indicate 0-90. PM me with your email address. Vital, I already have your email so if you think the 97 instructions will help then let me know.

I went to Radio Shack and spent under $9 for a bag of test leads with alligator clips and resistor packs with 47, 100 and 220 ohm values. Close enough for testing. The fuel sender connector was disconnected and the test leads were connectred to pins B (PPL) and D (BLK) of the vehicle side of the connector. The leads were long enough to extend out from under the car so I didn't have to keep crawling under. I connected the three resistors one at a time, turned the ignition on and watched the fuel gauge. For you, the 220 resistor should make the gauge display nearly full, 100 about 1/2 tank and 47 on E. I would give you my results but that would just confuse things as I'm trying to get a 97 cluster to work in a 93. The fuel level signal on the 93 doesn't go through the PCM as it does on the 97 and I'm assuming on the 99. If the gauge displays correctly with the three different resistor values then the sender is at fault.

One thing I did learn today is that the rheostat on the 97 sending unit was easily removable from the sender assembly. I wonder if just the rheostat can be replaced rather the entire sending unit assembly. The sender I bought for the 90 was $118 but a rheostat might only be a few bucks. Something to look into.

as far as I know it is the original sending unit, cluster and tank in the car. My email address is macho_mike21 at hotmail dot com

Email is on it'* way

buick has the same prob. i was told it was buildup on the sending unit...the metal contacts that rub up and down the indicator no longer work right...something like that.

Same problem as who'*? Mine or his? We've described two different behaviors!

I would say yours and Mike'*. Mine was a self-induced problem.

Ya, but his behavior is still different than mine..

The result is different but the cause seems to be the same.