Jeep Wrangler Forum banner

1 - 15 of 15 Posts

·
Registered
Joined
·
52 Posts
Discussion Starter #1
Hi. In order to access the fuel sending unit sensor, do i have to drop the gas tank in a 2007 jku? A happy new year everybody!
 

·
Registered
Joined
·
6,202 Posts
what is the issue that you are having? What is the gripe?

That doesnt look like the sending unit connector. That looks like the EVAP connector. The fuel sending unit connection is a flat connection like this.
 

·
Registered
Joined
·
52 Posts
Discussion Starter #4
I get the empty fuel tank light always... since last weekend. And this cable is loose, but i can't figure out where to connect it to. Cant find the other side. Before last weekend it i didnt see this loose plug and the fuel gauge worked fine.
 

Attachments

·
Registered
Joined
·
6,202 Posts
That is strange.

I just went and looked at my jeep because the fuel tank is removed, I couldnt find that particular connector anywhere. It's definitely not the same connector as the EVAP.

It may be the fuel sending unit, perhaps because it is an emissions system it could be different in your part of the world.

I dont recognize that skidplate in your video so it's hard for me to know exactly what area of the jeep I am looking at.

Here in the US, we have had the same fuel sending unit since 05. Yes you read that right, the TJ's were the same for a bit.
 

·
Registered
Joined
·
52 Posts
Discussion Starter #6
Thanx for looking! This one was imported from Texas in 2008, but 3rd world mechanics have improvised a LOT since then : ) So im trying to get all the improvised parts back to original. Whats even stranger is that my fuel gauge was working until last sunday. And after going off-roading for the first time, it stopped working, i looked under the car and found this loose plug i didnt notice before, but nothing to connect it to. Looked for half an hour. Im puzzled.
 

·
Registered
Joined
·
6,202 Posts
Welp, mine was purchased in Texas as well!

Maybe there is something different on the older JK's that I dont know about. Mine is a 13.
 

·
Registered
Joined
·
8,968 Posts
The fuel sending unit is part of the fuel pump mechanism in 07-17 JK's and it isn't serviceable. The tank has to be dropped. It's a "sweep" board that's incorporated into the fuel pump. The only part of the fuel pump that can be seen is like in the photo Tweak posted in #3 and it would look similar to the photo on the left. If your fuel gauge is working then there's another issue. If the gauge constantly reads empty then it could be the sending unit or a bad connection. There are electrical and Evap connections in the area of the fuel tank. It's possible that you can't see the connection on top of the tank. If you use a small telescoping mirror that should help.
 

·
Registered
Joined
·
821 Posts
Interesting. I have a '15 JKUR with about 34k miles on it. If it gets below around 50 degrees, gauge shows completely empty, but no fuel light. Anyone else have this issue?
 

·
Registered
Joined
·
52 Posts
Discussion Starter #10
Aha. So maybe this cable has something to do with the evap system, but then again, there must be a cable going forward for the fuel sending unite somewhere too, right? Wednesday I will drop the tank and see if i can find the issue.
About the temperature.

It actually happened at 5400m where it was colder and lower air pressure. I had real trouble starting the car. I have to clean the throttle body too (maybe even replace) because the throttle body light is an issue i have often, but it was worse up there. And then the fuel gauge stayed at the empty position and the light came on too.

I though it must have been because of the off-roading, but maybe its really because of the temperature / lower air pressure.
 

·
Registered
Joined
·
52 Posts
Discussion Starter #11
Looks like I found the issue - and it's linked to an earlier post. My alternator is overcharging and i get P0463 and P2138 (voltage too high for fuel sending unit AND throttle body) In addition I have P0403 which is probable that EVAP cable i saw.

So My alternator gives me 14 VOLTS when the car stands. and a 16.4 while driving.

I think it can only be voltage regulator in the PCM, because it has stayed at 14Volts since the day after I changed the battery, 4 weeks ago.

A lot of really bad mechanics have messed with the cables in this car, so is it possible that they connected a wrong cable to the PCM and now the voltage regulator tries to maintain 14 Volts when the engine is OFF while it should maintain that voltage when the engine is on ?

They also tempered with he cable to the PCM.
 

·
Registered
Joined
·
6,202 Posts
Aha. So maybe this cable has something to do with the evap system, but then again, there must be a cable going forward for the fuel sending unite somewhere too, right? Wednesday I will drop the tank and see if i can find the issue.
About the temperature.

It actually happened at 5400m where it was colder and lower air pressure. I had real trouble starting the car. I have to clean the throttle body too (maybe even replace) because the throttle body light is an issue i have often, but it was worse up there. And then the fuel gauge stayed at the empty position and the light came on too.

I though it must have been because of the off-roading, but maybe its really because of the temperature / lower air pressure.
Dont drop the tank. It goes to your evap. I just saw my old evap sitting in my garage and said HA that looks about right.

I can explain why you are having a fuel gauge issue because of the evap. The signal goes to the evap in some way or another telling it how to operate because it operates differently depending on fuel level. I am actually thankful for this thread because I have a fuel gauge issue as well. I replaced my whole fuel system with a fuel cell using the JK fuel sending unit and removed the evap completely. I designed it so that the float on the sending unit should work just fine and show the level in the cell, but it basically starts out at half tank and sits there until it is empty. I am going to plug the evap back in and see what happens. If that fixes my issue, I should just be able to find the resistance of the evap internals and simulate it and ill have a working fuel gauge.


And here is the plug, took some searching for it but I found it.
 

·
Registered
Joined
·
6,202 Posts
As for the alternator, I would have your battery and alternator tested.

 

·
Registered
Joined
·
6,202 Posts
1 - 15 of 15 Posts
Top