Changed fuel type, now gauge is inaccurate

[DAW]

So I converted an LD28 (diesel) engine to run on gasoline by adapting an L28E aluminum head/fuel injection/ECU, etc. It's strong, reliable, and has many features that a stroker L28 conversion lacks (like 140mm rods, large floating wrist pins, etc). However, the gas gauge doesn't work in the car (it's pinned on "full"). I've assumed that the gauge was inoperative in the car before I got it (diesel Maxima) but it just occured to me the other day that the problem may be related to a calibration difference between the difference in density of diesel fuel vs the gasoline which I now run in the tank. I'm wondering if I could add or remove resistance into the circuit for the tank sender unit to compensate. I searched for chemical and physical properties of petrochemicals on the web but got a bunch of advertisements for textbooks.

 

I can head for the library, but do any engineering types know if I'm barking up the right tree? DAW

[Mike kZ]

Why don't you buy a new sender for a gas Maxima?

[DAW]

I've got another instument cluster (has a tach and no glow-plug indicator) so I guess I'll just swap that and eliminate the gauge variable. I guess the density variable was wishful thinking to not have to deal with the sending unit. I can either continue to use the trip odometer between fill-ups or fix it. DAW

[Pop N Wood]

The densities might be different, but I doubt it would cause this problem. The read out might be inaccurate, but I doubt it would be pegged at full all of the time. Probably a broken gage or sending unit (I assume it is a float type sending unit?) Try pulling the sender and manualy moving it up and down to see what happens.

 

Could something in the sending unit be incompatible with gasoline and have disolved?