Fuel gauge is spastic

[torq455]

I've searched and can't find anything that addresses my problem. My fuel gauge will intermittently jump from 1/2 tank to full tank a few times. I'm assuming that means the fuel sending unit is going bad. Correct?

[robertisaar]

could be the sending unit, could be the guage itself, hell, it could just be a flaky connection somewhere...

[torq455]

only does it when i take a long left turn and the gauge reads lower.

[robertisaar]

that doesn't sound spastic at all.... just sounds like the float is moving with the level of the fuel.

[torq455]

no, it jumps.

[phonedawgz]

Its very most likely a bad sending unit.

[86FieroSEv6]

GM fuel gauge senders tend to suffer from the newer gasoline formulations, nearly 90% of sending units I've replaced have all come up in the last ten years. From about 03 onwards models it hasn't been too bad, but earlier models are definitely affected and not just due to age either.

[Tbay99Venture]

It was a few years ago, but a class action lawsuit here resulted because of high sulfur content in gasoline sold by a major oil company. Apparently that corrodes the sending unit. Perhaps there's spotty corrosion on his sender?

[torq455]

maybe, it's been reading fine since.