Not your typical gas gauge issue

[Tbauer729]

I have a 95 Tahoe 4dr/4wd with the 5.7 engine. Everything I read has people saying the gauge dance and wiggles and what not. Mine only does that when it's low on gas and I'm going highway speed around a decent corner. It'll bottom out and smack the other needles. That's not my issue. A full tank reads "E" and when it's empty, the gauge shows just barely past the 3/4 mark. Is something wired backwards? I bought the truck from an idiot kid, so I wouldnt be surprised with all the other small problems I've encountered.

 

[lesterl]

95 IIRC should not have the Hummingbird issue as it should be wired to the sender in the tank and not ran off the PCM.

Could be a bad ground on the sender I suppose....

 

[h82work1]

gas guage

Lester

I have the same problem mine is a 97 so what is a pcm I put new sending unit in gas tank still not fixed

 

[lesterl]

The PCM is the computer on the Vortec engines it is under the hood on drivers side wheel well. It reads the sender in the tank, computes a value, and modulates a signal to the dash guage.

The problem is as the gas guage ages (it is filled with a silicone dampening fluid) it starts to vibrate to the modulated signal (if you have the cover off you can feel it vibrate before and after the repair, but after the repair it looks solid).

I think 1997 was the first year to use this technique and it sucks, the newer body style (2001+ use a stepper motor instead of a linear motor (ours) and they have their own failures). These motors for our gauges are not available for purchase, but you can buy the silicone and get a syringe all for under $10 and it takes literally 5 minutes to fix.