Fuel sending unit buttstuffog 19gal tank vs 22gal

December 11, 2016, 10:24:30 AM

question some of us have had........
"why does my fuel reading / needle seem to move quicker in the middle range and much more slowly on the F or E needle positions?

FYI
I upgraded from 19 to 22gal fuel tank.

here are some observations.....

fuel sending unit resistance readings are per the evtm ratings listed for an buttstuffog guage.
while the unit is outside the tank,, all readings are as expected.

when the oem fuel sending unit is installed in the original tank, the float hits the bottom and the top of the tank early.
this reduces the "range" of resistance sent back to your guage.

when the oem fuel sending unit is installed in the 22gal tank, it never touches the bottom but does touch the top.

I am bringing this up because i dont think we have ever discussed it before. It appears ford used the same sender for both tanks 22gal and 19gal.... the 22gal is around 9'' deep and the 19gal is around 6.75'' deep with respect to the area the sender lives.

Fuel sending unit buttstuffog 19gal tank vs 22gal

Reply #1 – April 03, 2017, 03:52:37 PM

It is possible to fix that by modified thick film rheostat (AKA sender unit). I'm thinking about this for quite a long time. I already have a spare rheostat to play with. If there will be an interest I may dig all my old notes and try to create a new one based on your needs.
It is also possible to create a PCB style variant, which is easier to make for prototyping purposes.