I just bought my first Volvo, its a 1991 240 wagon. I'm working out all of the quirks and trying to get familiar with volvos. My fuel gauge is not working so I took the cover off above the tank to inspect the wires and the electric plug was just floating around. The prongs were broken. I also hear the fuel pump humming in the back so I am assuming the in tank pump is bad. Would the humming sound be coming from the main pump? Has anyone repaired the sending unit wiring..I would like to save 200$ if I can. Does anyone have a picture of what to connection should look like. Thanks in advance.

 

cleanflametrap.com has a complete writeup on dealing with 240 tank pump/sender assemblies.

the main pump is on the bottom of the car under the back right seat, and yes, it makes a 'whirr' sound. the tank pump makes more of a pffpffpffpffp sound (soft bronx cheer?). with a non-functioning tank pump, your main pump has to work extra hard, will be noisier, will wear out sooner, and you'll quite possibly have fuel delivery issues when your gas tank is below 1/2 full.

 

I'm not so sure if the tank pump is bad. It has a bit of a rough idle and is hard to start when the engine is warm. I turn the key and put my ear to the tank and I don't hear the pump. Thanks for the link

 

well, if the wires are completely disconnected, it can't possibly be working. afaik, there's 3 wires to the assembly, ground, power for the fuel pump, signal from the fuel level sender.

 

Thank you. I assumed all of the wires were for the fuel guage..I wasn't even thinking power to the pump.

 

Check out this site. If the point where the wires goes into the tank is broke off due to rust, etc., then the only real choice is to replace the sending unit. The aftermarket ones run around $200. If you buy one, check the wiring on them against your old unit (and a wiring diagram) as they seem to come from the factory wired incorrectly.

Also, here is the link to flametrap.com that has a great writeup on diagnosing and removal:

In the Tank - 240 Volvo Tank Pump and Sender

 

Thanks guys. I was hoping I could just solder the wires. Guess I'll go with a new sending unit. The reason I wanted to rebuild mine is I replaced a sending unit on my jeep and the unit was such poor quality.

 

there's certainly different grades of replacement parts... real volvo blue box stuff is generally the best, but of course its expensive. a couple dealers run webstores (tascaparts, volvopartswebstore) where they discount real Volvo parts 25-40%. Several of the independent parts dealers (IPD, FCP) stock quite a lot of 'OE' parts made by the same vendor that made the volvo parts, generally these are just as good for quite a bit cheaper. then there's the no-name chinese stuff thats cheap, but often total junk.

 

I tried to "rebuild" mine when the hermetic seal where the wires enter the tank failed. I used epoxy to re-seal it. Unfortunately the epoxy did not hold up to the gasoline and over time started to leak. Only solution was a new unit.

The build quality of the aftermarket unit looked decent and has worked fine - other than the wires being switched. Really, the only thing that seems to fail on the units - including the Volvo originals - is the top rusts out. To remedy this on my aftermarket one, I painted the top with POR.