fuel gauge

[rhgibson]

I have a 99 Tahoe and for a while the fuel gauge has been shutter back and fourth really fast. A while back I replaced the fuel pump assembly. Then today on a 250 mile trip the gauge just went around to upside down. While stopped at a rest area I turned the key off and on and the gauge went to spinning around. After leaving the gauge just goes to working upside down. Does anyone have a clue as where to start. Thanks

 

[lesterl]

Bad sender in tank? Ground the purple wire from the tank and see if it goes to the extreme. The PCM controls the dash guage on this rig so the purple wire feeds the PCM, the PCM modulates a signal to the guage. It could be a bad guage, you can get it sent off for a rebuild also...

 

[2000tahoez71]

I have never seen a GMT400 that had a gas gauge that worked right. All shudder really fast, and mine jumps when it's put in park from 3/4-F. It's fairly accurate, but stays on full for a while and once it hits 1/2 tank, goes down pretty fast.

 

[lesterl]

http://www.gmt400.com/forum/showthread.php?15139-HOW-TO-Fix-Bouncy-Hummingbird-Fuel-Gauge-Needle