[Mgs] 1974 MGB fuel gauge problem

[wkilleffer at comcast.net]

Hey Everyone,

A couple of years ago, I noticed that the temp gauge and fuel gauge on my 1974 MGB were reading quite high. Temp gauge was pegging the H, and the fuel gauge couldn't be trusted. I learned about the voltage stabilizer behind the dashboard, and discovered that it had been bypassed. I hooked the gauges up to it, and they worked properly. Both seemed reasonably accurate.

Now, over the past couple of months, the fuel gauge has developed some kind of fault. Most of the time, the needle barely moves away from the E. It moves just enough to show that it's responding to electrical input, but no more. Now that the weather is getting hotter, I've noticed something odd. The fuel gauge will start working and give what appears to be an accurate reading. I reset the trip odo every time I fill the tank, so based on that mileage, the gauge is true. It will work for a few minutes, then it will go back down to near E.

I replaced the sending unit in the tank about 7 years ago. The temp gauge never has a problem.

Also, this doesn't happen every day.

What are some possible fuel gauge faults that could cause this?

Thank you,
-Bill