Problem with a '91 Nissan pick up fuel gage. When new, the gage read a little past the full mark when the tank was filled. Over time, the gage would read almost full when the tank was filled. At this point, the gage barely reaches the 3/4 mark when the tank is full. Could there be a resistor somewhere that has slowly gotten worse? If the problem is in the tank, is there an access panel in the bed for tank maintenance? The truck had a bedliner installed since new, so I have never seen the inside of the bed. Any ideas would be greatly appreciated.
thanks

There is no access panel to the pickup truck fuel tank. You'll have to remove a small protective shield at the front of that tank (2 bolts), disconnect the plastic shield at the filler hose in the wheel wheel well (3 screws), loosen the filler neck from the filler cap (three screws), 2 bolts at the front of the tank and 3 bolts at the rear of the tank. Suggest you burn most of the fuel out of the tank before you drop it. Also get a new O-ring for the tank assembly too. Hope the float on the sender arm isn't leaking or you'll have to spend $270 for the whole assembly, plus tax! Oh, and use a stubby no. 2 Phillips screwdriver to loosen the clamps on the two fuel hoses at the gas tank. You don't have to remove any other hoses, as to remove the tank you'll have to feed the filler hose down into the frame as you drop the tank.

Best of luck.

Oh, forgot to mention that you should double check that all wires inside the fuel tank are reconnected prior to sealing everything back up. There is nothing like completing the job and then realizing that you didn't plug something back on. Ruins your day!

My truck seems to get good gas mileage, even when driving around 65mph. But if the fuel gauge is at less than half, it will drop pass empty in a matter of minutes if I am going around 65mph. Then if I slow down, it will jump back up to around half full?

All ideas welcome.....

- Matt

Oh oh. Sounds to me like you're going to find a broken wire on the fuel tank sending unit reostat windings. The dealer will sell you the whole thing which includes a new fuel pump. ....about $270 which includes the large O-ring for sealing the unit back into the tank, plus tax. Don't over torque those little screws holding the unit into the top of that tank. Strip one of those out and you'll have a real problem! :iceslolan

Oh oh. Sounds to me like you're going to find a broken wire on the fuel tank sending unit reostat windings. The dealer will sell you the whole thing which includes a new fuel pump. ....about $270 which includes the large O-ring for sealing the unit back into the tank, plus tax. Don't over torque those little screws holding the unit into the top of that tank. Strip one of those out and you'll have a real problem! :iceslolan

But is not a serious problem right? I mean, as long I don't run out of gas. Its just the gas level reading that's off? Not actually losing gas right?

- Matt

Yeah, it's just a faulty indication. One way to determine where exactly empty really is, is to carry a gas can along with fuel in it. Drive until you run out of gas. Now you know where the true empty indication is. That can of gas is so you that don't get stranded once you find out.

When replacing the sender unit, is calibration necessary or possible, or is the new unit factory set - just plug and play?
Thanks,

No. There is no way to calibrate the gauge. It's "Plug and Pray," just like MS Windows. I still think that you should find out where empty truly is. Carry that extra can of gas with you and don't run out in heavy traffic. Only then will you know when "empty" really means EMPTY. As the fuel gauge sits exactly on the empty mark, make note of your odometer mileage. When it runs out of gas, see how many miles you traveled to determine the accuracy of the sending unit.

Hey MattSimon,

I'm looking at my fuel sending unit that the dealer replaced for no good reason that I can see? It isn't wire winding like on most older cars. It's a printed circuit with the "windings" as part of the board. If you want this one, e-mail mtnpilotdiver@msn.com. If you actually put it to use, you can refund me the Priority Mail charge. Hell of a lot cheaper than buying a new one! I'm not selling it: I'll give it to you.

I've got this same problem. Last year I decided to find out where "empty" really was. I filled up the gas can, and headed for home, 300 miles away, with about 3/4 tank of gas. A nice drive through quiet farming country with enough gas stations along the way, but without too much traffic so running out of gas and pulling to the side of the road would not be a problem.

I made it all the way home. That's when I learned that I have a 21 gallon tank, even though when I fill it, it's never more than 18 gallons. I wish there was an easier way to fix the level indicator.