I recently built a 24 gallon fuel cell using the factory fuel pump assembly from a GMC Jimmy 2 door. Factory fuel tank was ~18 gallons bone dry. I changed the value in the tune (PCM was from a Suburban 5.3) from 31 gallons to the 24 gallons I'd like it to show, and I copied over the sender/level values from the Jimmy into my tune.
No matter how much fuel is in the tank, my gauge reads more than full - 125% full. It's way beyond the full line. I've always just known I could get a minimum of 200 miles per tank, so I just fill up around then but I'd like a working gauge.
Any tips?
Tune attached.