You mean the fuel sending unit? If yes, it is inside fuel tank. To down the tank to have access to it, as it is on the top.
The fuel sending unit is located inside of the gas tank.
near the oil filter
The oil sending unit is located on the top of the turbo on the 94 turbo diesel 7.3
you have to remove the oil pan and replace the pump
right above oil filter
Right behind the distributor, in the very edge of the block.
Usually right behind the distributor. in the back of the block.
The oil pressure sending unit on a 4.3 engine is located on top of the engine, at the very back of the engine, next to the distributor on the drivers side. I remove the distributor to gain better access to the sending unit.
I've just replaced a sending unit on a 94 S-10. To my knowledge, the sending unit only tells the gauge what to read so you can see it on the dashboard cluster...
I have a 94 e150 w/351 or 5.8 liter and the sending unit is found on the lower right front of the engine facing the engine.
It is the switch at the very back of the engine where the engine and transmission meet. and just to the driver's side of the distributor
Check the oil pressure sending unit first. The oil filter could be bad or clogged. The oil pump filter screen might be clogged, or the fuel pump could be bad.