Genright fuel tank, chokes when tank topped

[stickandrudder]

Hey guys,

Just installed a genright tank, and when I really top off the tank, the Jeep intermittently chokes on acceleration, or when cruising at rpm. As soon as I burn about a gallon or two down, zero issues. It’s not a TPS, CPS etc issue. With the tank install a new Bosch fuel pump assembly when in at the same time.

Can a pump die if it gets covered by too much fuel? Could it be a vent or vacuum issue? It’s peculiar to say the least.

 

[stickandrudder]

97 btw

 

[RCP Phx]

Have you called Genright? I would suspect a issue with the vent/roll-over valves and the fuel canister. I know that when I fully top off my ZJ tank I can smell gas vapors for a little while.

 

[Anak]

It sounds to me like a vent issue of some form. Sounds like there may be a vacuum created in the tank which will not allow fuel to flow freely. Once you create a large enough air space in the tank the air space acts as a buffer for that vacuum situation.

 

[tech1001]

I would check the evap system I bet it is sucking gas when the tank is that full .

 

[Tim_MN]

Stop filling tank when pump clicks off ?

 

[RCP Phx]

For $1400 Genright better help out to makes things right! Although my ZJ tank only holds 27.5gals it also didn't cost me anything but the time to install it.

 

[freggie]

I don't know about the jeep systems but my chrysler van has a check valve for the evap system and the check valve is known to go bad and fuel will get sucked into the engine and make it very rough idle and even stall out the engine every time the tanks filled full.

 

[stickandrudder]

Been on work trip past couple days, thanks for the response guys. The fuller the tank, the worse it gets, and I’ve also noticed I can make it sputter if I’m at partial throttle and just come off the power ever so slightly. Really like if were a vacuum issue. I can really open the throttle up and it’ll be ok, mostly. Then after a couple gallons are burnt it runs like a champ. I’ll call genright tomorrow.

 

[Rob Mayercik]

Can you try running on level ground with the gas cap slightly loose (so it can breathe through there in addition to the "right' places)? Might be a good data point for when you talk to genright.

 

[RCP Phx]

I don't think that will prove/do much, the tank and engine breathe thru the evap canister that's why we have a pressure check on the gas cap.

 

[xdarrows]

Hey guys,

Just installed a genright tank...

I can't help you with your issue, but I'd like to know more about your experience. I just picked up my '99 XJ with a new Genright tank a little over a week ago.

How is your fuel gauge functioning? I still haven't figured out at what point it starts dropping from F and it seems like I still have a lot of gas left when it gest close to E.

 

[stickandrudder]

Well I think I fixed it. Years ago I had removed the evap charcoal canister, and just tied the input/output lines together with hose, I wanted more room to get to my oil filter. Well I figured I should probably try putting that back in before I called genright, and it seems to have fixed the issue. I really topped off the tank this time also. After running it a few miles I pulled the canister back off and raw liquid fuel came out of the smaller of the two lines, which I think runs back to the tank right? I’m not very knowledgeable on how that works, is the tank under a vacuum normally? It would explain how raw fuel would slosh into that vacuum line and make its way forward I guess and act like a physical plug in the vacuum system. I’m assuming the canister acts as a sort of vacuum depository like the vacuum ball, and is allowing the system to absorb the fuel being sucked in. Not sure what the long term consequences of fuel dribbling into the canister are. Anyways, thanks guys.

 

[stickandrudder]

I can't help you with your issue, but I'd like to know more about your experience. I just picked up my '99 XJ with a new Genright tank a little over a week ago.

How is your fuel gauge functioning? I still haven't figured out at what point it starts dropping from F and it seems like I still have a lot of gas left when it gest close to E.

I can’t help you very much yet tbh. I have a brand new Bosch fuel unit in it and the gauge is working fine, tho I think it’s burning at least 4-5 gallons before the needle comes off its peg. I’ve only let it get to exactly the 1/2 point and the tank took 17 gallons. Been topping it off so much lately I haven’t tested it further yet.

 

[xdarrows]

I can’t help you very much yet tbh. I have a brand new Bosch fuel unit in it and the gauge is working fine, tho I think it’s burning at least 4-5 gallons before the needle comes off its peg. I’ve only let it get to exactly the 1/2 point and the tank took 17 gallons. Been topping it off so much lately I haven’t tested it further yet.

Thanks! Any info would be great to compare.

For instance, when mine is solidly on "E", there are still over 3 gallons left in the tank.