flyeri

Last year, thinking I had bought some bad fuel I removed my tank, cleaned and installed a new fuel sending unit as the old one had some corrosion on it and in the tube itself, and it indicated 20-110 ohms rather than 0-90. At this point my fuel gauge worked very well, no jumping around, only small movements in curves and acceleration and braking. The gauge seemed ok for a while with the new sending unit but soon started jumping around while driving. It seemed worse when the gauge indicated between 1/4 and 3/4 levels but never really smoothed out anywhere. It would jump up and down as much as 1/4 tank indications.

So as an experiment I cleaned up the old unit and reinstalled. An ohms check showed the same 20-110 indications as before. After filling the tank the jumps were back, immediately. So now, do I have two finicky sending units or has something else happened in the system? I have read all of the info from Willcox and they don't address this. The wiring appears to check out ok but I can't tell what happens with vibrations. On another board I read about a buffer of sorts, within the gauge, that smoothed out the needle movements that would be caused by sloshing but cannot find anything about that on our cars. So what trouble shooting suggestions might you guys have? All help appreciated.

toobroketoretire

I would guess you either have a bad ground at the tank unit or a bad hot connection as either would cause the symptoms you're describing.

flyeri

I sent Willcox an email earlier today and just received this reply.

The fuel gauge has a dampening fluid inside the actual gauge. When a gauge starts swaying, in most cases the fluid is gone from inside the gauge and it is not something you fix. The cost to repair will exceed the price of a new fuel gauge.

Willcox

With that information I will check grounds and connections again and if that yields no results I'll go with another gauge.

Thanks Willcox

0Willcox Corvette

My pleasure..

7T1vette

You may also have a ground wire or signal wire that is failing from wire 'fatigue'. If a wire flexes too much, it will start breaking down and resistance will vary with the wire movement. If you find either of these wires having freedom to wiggle around when you drive the car, a bad/frayed wire (internally) may be the problem.

CAREFULLY checkout all possible wiring problems before changing out the gauge. Gauge failures are relatively rare.

flyeri

I'm going to check the wiring pretty close. Thanks. Changing the gauge is not on my list of fun things to do. Changing the engine is easier.