HELP......I have run out of gas four times since I have had my 92 YJ.....that is since May of this year. My gauge reads just under 1/2 tank...and it starts to spit and cough......that gives me a few miles before it dies. I get about 140 miles before I start to panic. Any suggestions.....new sending unit, new gauge.....
?
EDIT: correction, i would test the gauge first by unhooking the connector at the gas tank and see if the needle goes all the way down to empty - as described in the FSM procedure below (i just realized that is the easiest way in your case to tell if it's the sender or the gauge).
this is what i would do
measure the ohms on the sending unit when you know the tank is almost empty with a multimeter - i can't remember what the value is but you could probably do a google search and find out what it should read. fill up 1/2 tank and measure again, then fill up all the way and take a 3rd measurement - if the readings are correct as per specs (or close since you won't know if it's all the way down) then you know the sender is ok. If the readings are off then you need to replace the sender. I think mine is an 80 ohm ('95 YJ) and would read close to zero when the tank is full.
I think you have a TJ (EDIT: you have a YJ, just read that in another thread), but the idea of how to test it i would think is the same as with mine - here's the testing method for the gauge for 95YJ/XJ from the FSM. the 3 pins mentioned are A-ground, B-fuel sender (that is in the center) and C-fuel pump relay (fuel pump 12v when the relay is active) - keep in mind that this is for YJ so if you use this method you should at least identify the connector pins to make sure they are the same and adjust accordingly if they are not - as per #1 below if you disconnect the connector that goes to the pump/sender your gauge should go all the way to zero (this seem to apply to you as your gauge never goes all the way down), if it doesn't go to empty it points to the gauge being the problem according to the procedure - i am pasting it from 95YJ FSM, page 5 and 6 from file 95XJ_8E.pdf
FUEL GAUGE
The diagnosis found here addresses an inoperative
gauge condition. If the problem being diagnosed is related
to gauge accuracy, be certain to confirm that
problem is with gauge and not with fuel tank. Inspect
fuel tank for signs of damage or distortion that
could affect sending unit performance before you proceed
with gauge diagnosis. Refer to Group 14 - Fuel
System for more information.
(1) Turn ignition switch to ON. Disconnect fuel
gauge sending unit connector. Connector is located
near the left front corner of the fuel tank. The gauge
needle should move to low end of gauge scale. If OK,
go to next step. If not OK, go to step 4.
(2) Connect a jumper wire between terminals A
and B in the body half of the fuel gauge sending unit
connector (Fig. 2). The gauge needle should move to
high end of gauge scale. If OK, refer to Group 14 -
Fuel System for procedure to replace sending unit. If
not OK, remove jumper wire and go to next step.
(3) Turn ignition switch to OFF. Disconnect battery
negative cable. Check for continuity between terminal
A in the body half of fuel gauge sending unit connector
and a good ground. There should be
continuity. If OK, go to next step. If not OK, repair
circuit to ground as required.
(4) Remove instrument cluster bezel and cluster
assembly. Disconnect instrument cluster connector A.
(5) Probe cavity B1 of cluster connector A. Check
for continuity to a good ground. There should be no
continuity. If OK, go to next step. If not OK, repair
short circuit as required.
(6) Still probing cavity B1 of cluster connector A,
check for continuity to cavity B of sending unit body
half connector. There should be continuity. If OK, replace
gauge. If not OK, repair open circuit as required
