'93 240 - fuel gauge working on and off

Is there any particular amount of fuel that causes this, for example a dead spot in the sender? You might also check the wiring to the bung plug on the tank, there's a connector there.

Nop, happens all the time, irrespective of the amount of fuel. This morning I drove to work, wasn't working when I started the car, Worked for less than a minute midway. That's it. Out of 45 minutes driving, it worked for about 30 seconds.

Thanks for any help/suggestion you can provide.

The fuel send unit / fuel level float in the gas tank may be corroded and deteriorating.

It has been a while, but I once owned an '85 240 wagon that had similar symptoms. As I recall we had to pull up a floor panel in the rear compartment to access the fuel tank. The fuel send unit is basically the port where the gas exits the tank, and there is an internal float mechanism that indicates your fuel level to the gas gauge. It sits on top of the fuel tank; it is a circular disc that locks in place with a half-turn, so you have to turn it back to unlock and remove the unit.

My buddy who is an experienced Volvo mechanic did the repair in my driveway. The part was pretty stuck, so he had to beat it loose with a large screwdriver and hammer - a delicate operation! Careful to avoid getting rust/debris in the gas tank! Also no smoking! Anyway, once he installed the shiny new send unit the gas gauge worked like a champ.

I recommend leaving this operation to an experienced mechanic, due to the fact that you're dealing with gasoline, fuel tank & lines.