Weird fuel gauge issue

[daSNAK3]

First time I’ve seen this happen. I had a full tank to start my day, been driving around today without issues. Stopped at the car wash to rinse some bird crap off and left the car running while washing it, when I got back in the car it said I was completely empty on my gauge and the center screen said “- - -“ to empty and the fuel light was on. I started my drive home and after about 3 miles of driving it went back to normal and reading correctly again, still well over 3/4 a tank and showing 147 miles to empty.

Anyone ever experience this before?…

Sponsored

 

[SHOdaddy68]

Sounds like an intermittent short in the sending unit.

 

[SheepDog]

First time I’ve seen this happen. I had a full tank to start my day, been driving around today without issues. Stopped at the car wash to rinse some bird crap off and left the car running while washing it, when I got back in the car it said I was completely empty on my gauge and the center screen said “- - -“ to empty and the fuel light was on. I started my drive home and after about 3 miles of driving it went back to normal and reading correctly again, still well over 3/4 a tank and showing 147 miles to empty.

Anyone ever experience this before?…

could be that the float arm got snagged on the cross over tube, or that the sending unit wires shorted or touched each other. Did you install your fuel system?

 

[daSNAK3]

Yea I did it myself.

 

[daSNAK3]

Went to leave for work this morning and my cel came on, I turned around and took my jeep to work. Just got home and scanned it, getting P008A. My fuel pressure on my gauge looks normal.

 

[wingnutt]

Went to leave for work this morning and my cel came on, I turned around and took my jeep to work. Just got home and scanned it, getting P008A. My fuel pressure on my gauge looks normal.

internet high five for the jeep backup…mines a 2004 TJ

 

[Iamtimsweet]

I'll admit, I'm having weird issues but learned a few things. The higher the float, the lower the ohms are. So if the tank is empty, it's the highest resistance. If there's a break in the wires, it's infinite resistance. Makes sense right? Well, there's a catch. Our cars have 2. So the computer has to interpret the value and make sense of both. Here's a way to test. Hit and hold the OK button and then press the start/stop button without starting it. Hold it until the bottom of the center screen says ET. Means Engineer Test mode. Scroll up until you see a Fuel A and value. It will show you the liters (in L) and Gallons in (G). Mine said 8.99 gallons and the passenger was 43 gallons. Now I only have a 16 gallon tank. How does that compute? It doesn't. So My passenger side read well over the 158 ohm threshold causing a BS reading. I'm pulling my passenger sending unit tonight to re-measure.

 

[daSNAK3]

I replaced the driver side sending unit, having the same issue still... my fuel gauge is being really wonky, it will be half tank and as I drive it slowly climbs to full but it takes a long time.

Does anyone know if the passenger side sending unit and the driver side unit are interchangeable? is it the same exact part?

And does one side send a signal for empty - 1/2 tank and the other send the signal for 1/2 - full?.. or how exactly do they work together, trying to figure out if I should try replacing the passenger side sending unit or what.

 

[bigjake]

I replaced the driver side sending unit, having the same issue still... my fuel gauge is being really wonky, it will be half tank and as I drive it slowly climbs to full but it takes a long time.

Does anyone know if the passenger side sending unit and the driver side unit are interchangeable? is it the same exact part?

And does one side send a signal for empty - 1/2 tank and the other send the signal for 1/2 - full?.. or how exactly do they work together, trying to figure out if I should try replacing the passenger side sending unit or what.

Any update? I am having a similar issue. I installed a Fore Innovations fuel system. The gauge will not read above 1/2 a tank. I even pulled the hat and manually operated the float to the full position. Still will only read 1/2 full.

 

[daSNAK3]

Any update? I am having a similar issue. I installed a Fore Innovations fuel system. The gauge will not read above 1/2 a tank. I even pulled the hat and manually operated the float to the full position. Still will only read 1/2 full.

Not yet, just got my passenger side sending unit yesterday, might put it in tomorrow. I had no issues for 2 years, dunno why this happened outta no where.

 

[bigjake]

Not yet, just got my passenger side sending unit yesterday, might put it in tomorrow. I had no issues for 2 years, dunno why this happened outta no where.

Hopefully that’s it. Keep us posted!

 

[daSNAK3]

Hopefully that’s it. Keep us posted!

Are you getting a check engine light as well?.. just curious

 

[daSNAK3]

So I put in the passenger side unit. My gauge was reading under a 1/4 tank, and said 2 miles to empty. After I put it in, it was reading the same on the fuel gauge but 42 miles till empty, so improvement, seemed accurate. I went and filled up, the gauge was moving up while filling, it wasn’t doing that before. Thing is it stopped at 3/4 of a tank and the pump clicked off. It was at 10.5 gallons. If I had under a 1/4 I would think it would have had around 3 gallons.. so that would put me at 13.5 gallons… with a 16 gallon tank… something doesn’t add up.

It definitely seems improved, haven’t got a CEL yet, not sure if the pump clicked off too soon, I’ve had that happen before but not on this car… or if I’m still having an issue with the driver side sending unit. Sheesh. Guess I’ll drive around, watch the gauges, fill up again and see what happens.

 

[daSNAK3]

I ordered a new fuel filter and pre filter socks for my pumps today.. figured it wouldn’t hurt to change them out… then I went outside and was looking things over because of the long cranking times I’ve been having lately after not having any issues for 2 years now… I opened my FC2 unit and found these fuses melted down. No idea if any of this is related or not, but I pulled that shit out, cleaned it up and put new fuses in. I tested both pumps prior to looking at this unit and both pumps were working fine.

 

[daSNAK3]

Still having issues with the fuel gauge and CEL.. super frustrating.

No idea where to go from here. I’ve went over all the wiring. The CEL will come on and go away on its own if I don’t clear it, then come back. Today on my way to work, with almost a full tank of gas, it started at 3/4 and slowly dropped down to half tank by the time I got there, it’s only a 15 minute drive.

Sponsored