I hadn't had a fuel gauge problem with my 68 442 of owning it since 1987, until last year.
It happened upon first start after winter hibernation, the fuel gauge went way past full.

I'll have to do some testing later this summer, but lucky me, in the 66-67 Olds parts collection, there was NOS tank sending unit.

If it turns out tank sending unit is bad and I have to replace, I'll check ohms on new unit before dropping tank.


Mader

 

Mine does that intermittently and it is due to the brown sending unit wire behind the bumper. There’s a loose connection at the stud on the sending unit. I’m too lazy to drop the tank to fix it.


You can do a test by unplugging that wire at the connector near the trunk grommet. Ground the end of the wire coming from the front of the vehicle. The gauge should go to Empty. If it does, the issue is between that connector, the sending unit, and its ground. If the gauge does not go to Empty, the issue is forwards toward the fuel gauge.

 

^^^THIS^^^

If you end up dropping the tank to replace the fuel sending unit you might consider lining the inside. Even if it's not rusted and deteriorated.

https://por15.com/products/fuel-tank-repair-kit

 

Thanks Fun71 for info. I check grounds and harness before dropping tank.

Mader

 

Olds64,

I run 90 ethenol free in tank last few years and put scope down neck and tank looked clean.

About 7 yrs ago had to finally replace original fuel pump when it failed about the same time case cap seal got gummy... &$#@ ethenol. That's when I switched to 90 e-free.

Mader

 

At that point don't you just buy a new tank as the price is comparable?