TJ fuel cell issue

livetorun

livetorun

Mammary Enthusiast
Joined
Jul 20, 2008
Location
Louisburg, NC
I need some help with my TJ throwing a code with a fuel cell. Its a 2005 and I have an RCI fuel cell with the stock TJ pump in it. Im getting the loose filler cap code. I currently have the rollover vent plumbed through a hose with a filter on the end. Could this be causing the computer to think the cap is loose because it doesnt build pressure in the tank?
 
You are exactly right. The cap on the original tank has a one way check valve in it to let air into the tank as the fuel is used but won't let air/fuel vapor out.
 
I replumbed the lines last night. Just need to run it a bit and see if the light goes out.
 
You're better of to take it to Vato zone or Advance and just have them clear the codes so you know it will do the test again. Otherwise you have to wait until it decides to do the test again. (Which it may not even do with the faults stored.)
 
Wouldnt disconnecting the battery do the same thing? It still has to run 75 miles or so before it will register again.
 
Not necessearly(sp) there are "soft" codes and hard codes. Some have to be reset with a tool ie the hard codes some reset with a battery disconnect ie soft codes....
 
No. It will retest when it has all the criteria met to do the test. Don't know what that criteria is though.
 
livetorun said:
I currently have the rollover vent plumbed through a hose with a filter on the end. Could this be causing the computer to think the cap is loose because it doesnt build pressure in the tank?
Click to expand...
The 2 check valves on top of the stock tank run to the fuel management valve and hook to the leak detection pump. Where do you have the lines from the stock check valves routed to now?
 
The RCI fuel cell has three ports on top, a rollover vent, fuel line return, and fuel pickup. Im using a stock TJ pump with internal return so I had the pickup line capped and the charcoal cannister plumbed to the return port. On the rollover vent, I had a hose coming off of that with a filter on the end. I may have overlooked something but I believe the charcoal cannister only had 1 line coming off of it. That line splits and a small line goes to the front and with the other line going back to the tank as mentioned above. Here is a crappy cell phone pic.

IMG_0974.JPG
 
I was assuming that 05's were the same as 04's but after seeing the picture of your fuel pump I see that I was wrong, that thing looks nothing like the pumps on 04's and previous. I'm not sure how the Evap system is configured on 05's, any thoughts I had were based on the system on my 04. Good luck with it.
 
Caver Dave said:
Any chance you're plumbed into the wrong bungs?
Click to expand...
That was my first thought. Im sure about the rollover vent, it has a check valve that is suppose to close when inverted. But when sitting right side up, the check valve is open. The other two not so much. Im going to show my stupidy, but wouldnt the pickup and return ports both just be lines that empty back into the tank? Granted the pickup port should go all the way to the bottom and the return may end higher up.
 
Only asked because there were evidently a bunch of them that went out with mislabeled ports *and* I wasn't sure which port was which. However, about 20 seconds with a flashlight yesterday confirmed them on mine and are arranged just like you have them plumbed...

livetorun said:
I currently have the rollover vent plumbed through a hose with a filter on the end. Could this be causing the computer to think the cap is loose because it doesnt build pressure in the tank?
Click to expand...

That would be my guess... depending on WHERE the "tank pressure" sensor is located (OEM sending unit? Still mounted to factory tank :D )

To test that, you could cap it off?
 
That would be my guess... depending on WHERE the "tank pressure" sensor is located (OEM sending unit? Still mounted to factory tank :D )

To test that, you could cap it off?[/quote]

Everything that had a wire or hose on it, was taken off of the factory tank. I am using the OEM pump and sending unit. Is there a fast way to test capping the line? If I have to drive it 75 miles, it'll take forever to go through the process of elimination. It dosent see much road use anymore.
 
Back
Top