Heres the story I had to build a tank for my wagon 56 pontiac. Couldnt find a 56 poncho wagon sending unit so I used a 55 chevy. Its set up right when the float is all the way down its about an 1/4 inch off the bottom of the tank. So now it doesnt read right it reads full almost all the time. I can drive a week on full and it goes from full to a 1/4 tank in a day and a half. At 1/8 of a tank your walking feeling stupid. So Im thinking its got to do with omes (spelled wrong) and the new sender and old sender use a differnt amount of omes. Is there a way of recalibrating my gage to the new sender.
I thought all the old GM fuel gage senders were 0-30 ohm. Might double check that your sender is the correct one, it should read near 30 ohms resistance between the sender terminal and ground with the wire removed from the sender, and the tank full. Resistance would be less if the tank is not full, down to zero oms at empty. If the sender is giving the correct resistance, there may be some other problem....
The Jalopy Journal
