Erratic fuel gauge

[smlblk318]

Functions as designed when tank is full. Indicated level falls rapidly to 3/4 within 20 miles and reads almost empty after around 80. I know I'm not using that much fuel even with my heavy foot. Sending unit looks newish (I've only had the car for a few years and was always like this) but am thinking of changing it due to them being inexpensive. Is there any adjustments that need to be made when installing a new one? Could I have another problem other than the sending unit?

 

[Mike69cuda]

You likely have an aftermarket sender. They are not designed the same as the original. You will likely not fix the problem by replacing it. There is a device called a meter match that I used to fix mine. Look for fuel or gas gauge (senders) threads on here. There is a lot of info, as this is a common issue.

 

[Lord Sparky]

You likely have an aftermarket sender. They are not designed the same as the original. You will likely not fix the problem by replacing it. There is a device called a meter match that I used to fix mine. Look for fuel or gas gauge (senders) threads on here. There is a lot of info, as this is a common issue.

Correct answer. I also refill gas by mileage.

 

[Dana67Dart]

Post 4 has the graph...

Product Review: A100 Fuel Sender For 67 Dart