I feel foolish even posting this, but it's my only real problem with the rex. At just over half a tank my fule gauge reads empty. I know, not a catastrophy, but if someone would let me know how to fix this I would be greatly appreciative.

 

Is it always reading empty, or just as it gets lower

 

Sounds like a bad sender. I had the same thing on my SE. Below like 1/2 tank or so, the gauge would stop reading. New senders run around $100 or so. You could use a used sender, but with the work pulling the tank and all to swap, I chose a new sender. The other option is to just keep the tank full or use the odometer to figure when you need to refill.

 

Do they even teach spelling in school anymore? Just wundering.

Rich

 

my 81 has same prob. think i remember guy at nopi telling me he could get new one for 70. i just use my odm.

 

 

I'm assuming you caught my attempt at humor

 

Actually this could be a big problem because it might be the fuel sending unit in the gas tank and not the guage itself. You need to check both the ground for the guage itself and the ground for the fuel sending unit. When my Rx7 came in from California, last March, it had the same problem and it was the sending unit.

Keeping your tank half full to full at all times is only a temporary solution. Eventually the sending unit will fail entirely, the car will stall out, and you will not be able to start you car until its fixed. If the sending unit is bad just fix it

 

Huh?? The sending unit has nothing to do with the way the car runs. It just tells the gauge how much gas you have. Before my van died, I went by the odometer, because the gauge had gone bad, and I knew how far it would go on a tank of gas.

Rich

 

I have fuel sending units fail in both my 1985 Rx7 and Explorer and in both cases I was left stranded and in both causes the sending unit was the the problem.

 

I'll wait for others to respond to this, because I suppose there is something going on here that I don't know about, but I think that's crazy....the sending unit just tells the gauge how much gas you have...that's it. I can post the wiring diagram if necessary. The sending unit is just a variable resistor that provides a partial ground for the gauge.

Rich

 

Sending unit has nothing to do with whether or not the car will run. Running out of gas and clogging the fuel filter is a more likely scenario.

 

my fuel gauge has never worked since I purchased the 7..once in awhile it will temporarily work after a refueling...luckily my fuel light works and I've learned how far I can go on one tank...one day tho...the sender will be replaced

 

As mentioned I mentioned in my previous post the problem I had, with the sending unit(s), happened twice. Both times each car had at least half a tank of gas left after being topped off previously. I, to, used to guage refueling based on what the odometer said. Anyways both times the fuel sending unit was replaced the problem was solved, no other work had to be done on both occassions. I'm going to stick to what I've been saying just because of what I have experienced and based what work was done to fix the problem.

 

While you are sticking to you guns, and polishing them, (smart *** humor, no offence intended), take a look at the the wiring diagram for the sending unit/fuel gauge. You will find no interaction between the sender, gauge and fuel pump. It could be that when the sender was changed on the 7, a loose connection to the pump was fixed.

The sending units have 3 wires, 1 for the gauge, 1 for the low fuel light and a ground. The low fuel light will often work even if the sender is toast. For those of you who are familiar with the old style **** tuning radios, not the new digital ones, the fuel level sender works the same way. There is a bar that has a wire wound around it and a contact that slides across the wound wires that is moved back and forth by the position of the float arm. The needle on the gauge moves by the varied resistance produced, depending on the position of the float. The wound wires eventually break due to the rubbing caused by the pick up contact moving across them. Depending on how and where the wires break, the fuel gauge can give a partial signal, then drop to empty.

 

before you go waste money on a sender, check the wiring.

I had the same problem as you. At full tank it would read 1/2 and by the time it got to 1/2 tank it read nearly empty...


The fuel gauge works on resistance, so if you're wires are old and corroded they'll have more resistance and thus give the fuel gauge a bad reading.

The plug going into the sender on mine was loose and corroded. I cleaned it up as best I could and squeezed it a bit tighter with some needle nose pliers. To clean it up I sprayed both ends of the plug heavily with wd-40, liquid wrench etc and then just put it on and off 10-20 times until it looked like it was making good contact. and now my guage works perfectly.

 

agreed on saving money, however is there a way to get to the wires, without dropping the tank? if not I would just spend the money on the sender considering the work involved

 

Remove rear driver (US) wheel and then lift up on plastic inner fender well piece. The sender is right there, and you can access the bolts as well.

 

ha! a shortcut..sweet thanks!