Crazy Fuel Gauge

Feb 6, 2018
21
12
Heber Springs, AR, USA
#1
At every fill up, the fuel gauge goes crazy for a while. Up and down, then at half full, then settles at full. The needle stays at full till almost empty, then moves to just short of full. Thanks!!!
1997 wrangler, 4 cyl.
 

Chris

Administrator
Staff Member
Sep 28, 2015
33,275
20,458
Salem, Oregon
#2
Sounds like your float sensor inside the tank is going bad. If this is the case, you need a whole new fuel pump assembly, as I don't believe they sell the sensor by itself.
 
Likes: ALAN TUCKER

danof76

TJ Enthusiast
Nov 21, 2018
105
98
San Antonio, TX
#3
I'd guess either bad gauge or bad float. I know the YJs were notorious for busted gauges, mine had the same issue where it was either always full or random but never reliable. Given that it's a '97 I wouldn't be surprised if it was still using the bad gauge the YJ used.

If it's a bad float then you have to... what @Chris just posted.

If you don't know the float is literally a floating, buoyant doohickey on an arm that pivots about the fuel pump assembly in the gas tank. Based on where the arm has rotated a sensor will read it and tell the gauge what level the tank is at. I have seen one of those arms stick before but that was on a Chevy, no idea what the one in a '97 TJ looks like. Depending on how much work you want to go through you could buy a new one, take the old one out and give it a look over to see if it seems anything purely mechanical you could fix and give it a shot... or just replace it and be done with it (that's what I'd do honestly).
 
Likes: ALAN TUCKER

VegasOPM

New Member
Supporting Member
Jan 12, 2019
6
13
Vegas Baby
#7
I have a fuel sending unit issue too. I have an Check Engine light and the code said that the sending unit voltage was low. I swapped the sending unit and it didn't solve the issue. The gas gauge comes and goes while I'm driving- it seems to be a short or a connection somewhere that is making and losing contact as it hits bumps. Looking for guidance if there are any "known issues" with connections.