The Stovebolt Site Forums The Shop Area The Electrical Bay Gas Gauge inaccurate

There are 2 reasons this will happen...One: the sender doesn't register the correct 30 ohms (full) and 0 ohms (empty). Since yours doesn't seem like it is over-registering, I don't think you got the 0 to 90 ohm sender (which was common in newer GM vehicles). Two: you didn't get the float arm adjusted correctly when you installed the sender. There is a formula which I gave everyone 3 or 4 years ago, but sadly it requires some searching and digging to find it now. Essentially you shorten the float arm so that at full (where the sender lever will be stopped on the upper travel) your float just touches the top of your gas tank and at bottom it stops just a bit away from the bottom of the tank. There is one sender unit (designed and made in Taiwan by somebody who knew just what he was doing) and that is the one to get. It comes with the formula for the float bar included. It is sold on the big auction site of the internet by a seller whose ID is renbusan and it is about $30 including shipping.

If it were me, I'd get a handheld meter, remove the sender and check to see the readings at full and empty...and by that I mean where the sender stops will prevent up/down travel. Should be 0 at the bottom and 30 ohms at the top. I'll wait to hear and will look for my formula chart in the meantime.