Should the inline fuel pump have a loud hum when power is applied? Also, the fuel level gauge doesn't seem to be working. Anyone have a good way of testing it?

 

if the in-tank pump is dead, then the main pump under the car has to work a lot harder and is noisier. normally, it should be so quiet you can barely hear it.

 

If your fuel gauge isn't working and your main pump is noisy, more than likely your sending unit is failed. Power to the in-tank pump and the signal for the fuel gauge both run to the sending unit. Diagnosis and replacement instructions can be found here:

In the Tank - 240 Volvo Tank Pump and Sender

 

is this a 240 or 7/9 ? the fuse panel tests described on that cleanflametrap page are only appropriate on a 240, but the pumps themselves are pretty much the same thing. a 7/9 has a completely different tank access cover

 

Thank you so much for all of your responses. I will be ordering a new fuel sending unit.