Fuel Sending Unit or what?

[my01330ci]

I have an issue with the gas gauge. I'm thinking it is either the fuel-sending unit or the fuel pump. The gas gauge will read about 1/4 left and the digital readout will be around 90 miles left, but in actuality I'm running on empty. I use to be able to run this down to about ten miles left, but anymore around 80-90 I'm looking for a gas station. At times it will even begin to cut out. Any thoughts on this? If it is just the sending unit, I saw on the website it shouldn't be too difficult to replace. It's a 2001 330ci with about 135000 miles and still rollin' fine....

Any help is appreciated. Thanks...

[Jeron]

There are two senders, one in each lobe of the tank under each seat. You can use a multimeter to measure the resistance of the leads under the seat to determine which side is bad, on an empty tank of course.

The right (fuel filler) side has the pump and the sender on that side is attached to the pump. You may be able to replace the sender without replacing the pump but it probably isn't worth the effort.