Apologies...this is my third stab/new thread for this incessant problem that I'm still trying to understand. 99 sport (fuel pump in top of tank). My just-over-two-month-old new fuel pump abruptly started leaking. I have verified twice that the plastic retainer nut is on properly and fuel is not leaking out around that. The (very aggressive) leak is occurring where the fuel supply tube (single line system) connects at the top of the pump. I just swapped out the little plastic "fuel line retaining clip" (the tabbed doo-dad connecting fuel supply tube to the pump) again with no change except for the worse. I am not keen on modifying the set-up since it is a fuel line (and I have dependents).

Could something be causing an over-pressurized type situation that is forcing fuel out at that connection? Or could there be a venting issue that I could check? I am finding no leaks elsewhere - only at the one connection point (in pic). I also looked at the inside of the ends of the fuel supply tube as well, but there is no obvious damage, deformity, etc.
I don't want to give up and have a shop look at it, but I'm out of ideas and it's pushing out enough fuel to make it to the ground now (not to mention the incessant fumes are killing more brain cells than I can spare). Diagnostic ideas?

 

I'm not really your guy here, but a few things. I believe your pressure regulator is in the tank, and you can borrow a pressure gauge free. Test port is on the fuel rail. Yours is 49 Lbs? (I think)

Is that a "quick disconnect" fitting that's leaking? On my 90 those are a bit tricky. There are two O rings with a spacer between them. (You can't get the spacers, so don't loose any). Not sure if yours has that setup...an auto parts guy just might be helpful, also I believe there is a cheap plastic tool to disconnect...Idk!

Don't worry about the brain cells. You are just culling out the weak, and actually getting smarter! I find just one or two is KO.

 

Thanks Flintstone. I didn't think about checking pressure at the rail because the injectors are not leaking and I'm not experiencing any conditions suggesting lack of fuel or pressure up at the rail. Maybe I'm wrongly assuming that the problem is contained to the pump area.


But yeah - I wondered about O-rings possibly being used at that connector in the pic. When I originally put the new pump in, it was just a little plastic clip like in the pic (no O-rings), so I just replaced the clip the same way. The set-up does not appear to provide any extra space at all to accommodate any O-rings, although I seriously considered layering on some of those tiny rubber bands (used for braces) to see if that would help.
So...not understanding how the pump itself works, I wondered if maybe the plastic clip was not really the problem, but just a symptom of a different problem Research has not been kind to me on this one.

 

K,


I don't think you have a fuel pressure regulator problem causing a high fuel pressure situation, but it is not impossible.


That device on top of the fuel pump is the fuel pressure regulator/filter assembly. It regulates the fuel pressure to 49.2 psi +/- 5 psi. Pressures above this will be spilled back into the fuel pump inlet.


I think you may have bad O-rings in the quick disconnect fitting at the regulator outlet tube.


There is a short hose (tube) that has a QD on both ends. It connects from the regulator to the steel fuel line that goes to the fuel rail.


The OEM part number of this hose/tube is 52100037AD, called a Tube, Fuel Supply.


You can get one on-line or try your dealer.


Here's the Mopar America site that shows the cost.


http://www.moparamerica.com/oe-mopar/52100037ad


Dealer will charge you the MSRP.


This is the route I would go (replacing the hose/tube) before replacing the Fuel Pressure Regulator/Filter assembly.


Ken

 

Just for your info, here's some pics of the inside of the Fuel Pressure Regulator/Filter assembly:


The filter:





Regulator components:





Basic assembly:

 

Thanks Ken, I shall order and hope that does it.
Really, really DQ: can that supply tube be connected in either direction (meaning, it's not a one-way only mechanism?). Common sense says a "tube" is a tube is a tube, but thought I'd double check on that.

 

I think the new tube will have a blue retainer on one end and a grey retainer on the other end. There's no 'one way' mechanism but there may be a difference in the lock feature on the tube nipple that the retainer engages (?).

The blue retainer connects to the Fuel Pressure Regulator nipple.


Tip: before installing a QD make sure you apply a thin coating of motor oil to the nipple so the O-rings do not roll.


Pic of mine:





Nanner Nanner...I made an access panel to get at my fuel pump.

 

YES! I still have a blue clip connected at the hard line end, but pump had no blue replacement for the nipple, so used a Dorman replacement and haven't found a similar blue clip at local parts places. I didn't try to save the original blue one from the old pump's nipple (giggle) bc I figured I would probably mucker it up trying to get it off. Ordered the tube and I'll see if I can get a blue clip somewhere AND use a little oil (did not do that). Thanks. And yes, impressive little easy access hatch you got there. I probably have sufficient rust to kick one out myself haha.

 

No fix?

 

Ordered the tube from the link you posted same day (thanks again!). I'm hoping it will be at the house when I make it home today.

Some fun last Friday though...been keeping 1/2 tank or less til I'm assured it's fixed and don't need to drop tank again. Idiot light went off with gauge appearing approprite (consistent w/idiot light meaning I have approx 5 galls left)...15 miles later, I ran out of gas. Right across from a station thank goodness. :/

 

Clarify:


Low level light went OFF when you hit 1/8 tank? Is this when fueling up or running down?


The PCM only knows what the fuel level float/resistor is telling it. It puts then light on when the quantity reaches 1/8 tank.


As I recall (maybe) that you had an issues with your fuel pump connector. Could it be that you got some moisture in that connection and it is corroded a bit...

 

Sorry, low level light came on while driving. But it was an unpleasant shock to run out of gas only 15 mi later.

Re the connector- I did have to manhandle it a bit to disconnect it but I cleaned it out with a Qtip and elec cleaner before re-attaching it (all 3 times). Is that something I might then smear some dielectric grease on/around after connecting it? Seems like that might attract more dirt though.
I also worried a bit that the two elec wire ports (?) on top of pump towards rear of jeep were getting wet with the fuel that pools up there.
At any rate, I hope swapping the fuel supply tube out relieves the problem. Disappointed that I couldn't scrounge up anything beefier than the Dorman plastic retainer clips to use with the new tube when it gets here.

 

Hate to bring this old thing up, but did that fix the problem? Because I am having the exact problem with mine.

 

Thier last forum activity was 2016.

 

2000 Cherokee 4.0 Inline 6

Getting a lot of head scratches on this one. Auto parts stores don’t know, Napa doesnt know, local mechanics dont know
(Hopefully posting in the right place, this seems similar).

Start up is fine.
Runs fine.
After about 60-120 seconds fuel flows out of the filler neck/gas cap.
I have replaced the filler neck (not hoses)
Have also replaced evap purge valve (under hood)
Replacing evap purge valve solved code for evap leak. (no current codes)
No progress on fuel flowing out of filler neck yet.

It seems a vent is obstructed? but I’m just recently studying this system.
Trying to get the Jeep working so I can!