Gas Gauge Not Reading Full

[PeteyJK]

So how does this fuel gauge sender work anyway? Five years ago, I took the JK on the Rubicon and it took a few hits on the underside. The stock gas tank skid was bashed in quite a bit and the gas gauge would read 1/8 tank low when full. I removed the skid, took an anvil to it and bent it back into shape again. Once again, the gas gauge read full again accurately. Last year, the skid plate got bashed again and the gas gauge suffered the same outcome. Recently I pounded the OEM skid back into shape, installed a gas tank skid and the fuel gauge returned to normal accurate operation again. Last week, I swapped a different transfer case into the Jeep and had to partial unbolt the gas skid to get out the tranny crossmember. Upon reassembling, now the gas gauge is again not reading full- it's close, but not fully full.

What gives? Is the float just stuck? Anyone else have similar issues?

 

[benatc1]

I think it’s just a sick joke based in the times, “thanks for spending so much on filling her up! Just kidding your still short no matter what you do!

 

[pvkj454]

The TIPM receives a variable reading from the fuel sender depending fuel level. The TIPM calculates the level also using time and vehicle speed. The TIPM sends a CAN signal to the gauge cluster for it to display the correct level.

I replaced a defective sender in a Dodge pickup that would display 1/8 of a tank when completely empty. I would make sure the skid is not causing the problem now before replacing the sender.

 

[PeteyJK]

I just recalibrated my transfer case with the AEV Procal, since I swapped in a 4:1. Could this possibly be the issue, since I haven't driven more than 10 miles on it since? I did notice that after the recalibration, my running miles per gallon got adjusted. If so, maybe I just need to drive on it a bit?

 

[Seahawkfan]

I just recalibrated my transfer case with the AEV Procal, since I swapped in a 4:1. Could this possibly be the issue, since I haven't driven more than 10 miles on it since? I did notice that after the recalibration, my running miles per gallon got adjusted. If so, maybe I just need to drive on it a bit?

I'm still trying to figure out how or what " taking an anvil to it" means.? Maybe a BFH !! And how a bent skid plate can have anything to do with a fuel reading. You don't mention a dented tank. On your MPG you can drive a JK nice easy, keeping the rpm's down and not racing the engine a lot or at all, you can achieve a high MPG, then bomb up a hill or two and that 17 or 18 MPG will drop to 13 or 14 mpg real quick like. Again, not sure what a dented skid or calibrating a transfer case would have anything to do with a fuel reading.

 

[PeteyJK]

The anvil was really a 25-lb. vise, but I just kept dropping it on the dent to pound it out. The gas tank is nothing more than a plastic bladder sitting on top of the factory skid, so when the skid gets dented, the gas tank will follow. I don't know the relation of dents and how it affects the float, but when the dent came out, the gas gauge once again read accurately. And thank you, I understand how punching the skinny pedal will adversely affect the gas mileage. That's not what I'm talking about.

 

[cozdude]

Changing the transfer case shouldn’t affect the fuel reading since 2wd is the same ratio. The only thing I can think of is that your fuel pump float resistor is just worn out from the years and is giving you a False reading. Has a few dead spots. Or the float rod is ever so slightly bent making it not read full

 

[PeteyJK]

Changing the transfer case shouldn’t affect the fuel reading since 2wd is the same ratio. The only thing I can think of is that your fuel pump float resistor is just worn out from the years and is giving you a False reading. Has a few dead spots. Or the float rod is ever so slightly bent making it not read full

I think you're right about the float arm- this rig has been tossed around a bit. As far as the MPG counter goes, come to think of it, I reset it a week or 2 ago and I haven't been driving it much, since I've been working on it. Not many highway miles under its belt yet for this go around.