My fuel sending unit is not working properly. I would like to replace it. Who makes or sells the best unit. I know I'm asking a lot, but hopefully one that does not move from empty to full at every little bump or corner. I understand how they work. Maybe an upgraded model that has a bit more tension on the sliding bar inside the unit, or some sort of damping system, like a spring?
Thanks, Roger

Very interesting question.

More modern dash gages are thermally operated. Current that is proportional to fuel level passes through a "heater" in the dash gage. The gage needle moves proportionally to the heat generated. Since it takes time for the heat to change, the dash needle responds slowly to fuel level changes.

The Healey dash units are just a moving coil (plus some magnets) that responds instantly to current changes as the sender's resistance varies with it's float position.

Mechanical damping of the sender so that it doesn't bounce around as the fuel level changes does not prove to be consistent or reliable.


The operating current through the original circuit is designed to be low enough to prevent serious sliding contact arcing in the tank.

Electrical damping at the dash unit by use of a capacitor "might" reduce the bounce. HOWEVER, folks are reluctant to have a capacitor possibly discharge into the tank unit where it might cause a larger arc & explosion.

The other side of the coin is that many pumps that are mounted inside the tank actually have arcing brushes which are submerged in fuel & the fuel cools the pump. They don't seem to cause explosions.

Another possibility is to completely change the dash & tank units to non-original modern types.

If you wish to try a new scheme please let me know how it works out. I think I'll continue to use my calibrated measuring stick when I really need to know how much fuel is left.
D

Just buy the repro ones from the guy who sells them on ebay (NOSImports). They are very well made, look original, and are cheap. No need to make this complicated!

Hi Roger,
On your thought of a damping spring, how about installing an RC car shock? This photo is one for an 1:8 scale monster truck.