GrtLksMarlin

1999 XJ 4.0 Auto 4x4 190k-miles: Stalling issue... I believe fuel

Situation: We had heavy rains, the vehicle's fuel fill pipe is loose from cap (pipe rusted last inch to cap mount and is open, yet previously caused no issue), next day the vehicle begins to stumble then stall. Would restart, drive a short distance (half-mile), repeat. When it died (would not restart) added 5 gallons of fuel plus 2 bottles of dry-gas. Ran for 30 miles fine. Sat overnight, ran for 3 miles stalled again, cannot be restarted. Starts, then stumbles and dies in three seconds.
* I can hear the fuel pump start up.
* I 'believe' baffles in tank are rotted... although, at times they seem not to be (with low fuel a hard turn to left kills engine... other times, not)
* Local fuel is notoriously dirty.
* Recently reworked all of my grounds and wiring, including neutral safety switch and ignition switch, all with success.
* New battery, new starter, new alternator, new battery cables... seems to have no 'obvious' electrical issues.

Any thoughts as to what this might be or where I should investigate as a next step? I'll dump more fuel in it and see if i can get it home, then be checking back here.

Thanks for your help!

B.E.F.

PatHenry

I have to agree that the issue seems to be indicative of fuel issues.

Are you getting any check engine codes?

I would start with a fuel pressure check when it's running crappy or not at all and see if you get sufficient pressure.

My gut feeling is that the rusted fuel tank stuff - neck, baffles, whatever, might have caused a tear in the fuel strainer thing -- and/or -- sediment buildup from the open fuel tank is causing the fuel pump to fail. If you're dead set on keeping the Jeep, I would be considering a new fuel tank and fuel pump assembly and fixing the filler neck stuff.

GrtLksMarlin

Thanks Pat Henry for the response. Codes, I'm unsure of. I'd need to do a manual check (will look up that method) or take it in for someone to check. As to the rest, let me say this first.

EDIT: Manual check for codes (key on with odometer depressed, 000-999) yielded nothing except a readout of mileage.

So, it had 1/4 tank of fuel, I added 2-gallons bringing it up to just below 3/8 and it started and ran enough to get it home. I did feel a minor stumble or two, yet otherwise, severely weaving the vehicle, braking, and accelerating, I had no issue.

With that in mind, what might cause it to have trouble when the fuel is below a certain point? As said, at one time I 'thought' I had baffle issues, and it wouldn't surprise me. But, for six months now 'that issue' seems to have vanished (hard left causing a stall). As a side note, we have some 'borrowers of fuel' around here, so i routinely for years have kept it at 1/4 tank, running it till empty, then back up to 1/4 since it keeps them at bay. The jeep is ONLY used to run our dogs daily out on state land in the woods and swamps for 20-years now. 15-miles round trip 2x a day. So, you can imagine it has acquired some aromatic seasoning and that's all it is used for. I'd prefer not to make my hunting/fishing jeep into the dog jeep.

Any further thoughts? Thanks for your help.

B.E.F.

PatHenry

Interesting.. diagnostics is definitely in order.

Did you clean and tighten the grounds behind the cargo area driver's side trim panel? That's the ground for the fuel pump. If not, definitely do that first.

I'd definitely do the fuel pressure test. Go to www.cruiser54.com technical manuals link and get the FSM for your 99. It will have the detailed fuel pressure test steps. You can get a pressure gauge at your local autozone as a loaner tool and have them read the codes if any that are stored.

It would be worthwhile to replace the fuel filter if it hasn't been done in a while and you have dirty gas.

Driving as you describe with low fuel all the time is a good way to burn out a fuel pump since it uses the gas to cool itself. Running 1/4 tank constantly is not enough to sufficiently cool the pump.

So I'd do the trunk grounds and pressure test to start and go from there.

GrtLksMarlin

Thanks PatHenry;

Yes, those grounds (and all others in the vehicle) were repositioned to fresh metal, ends cleaned or replaced, etc. just a couple months ago. That said, the wire leads to the pump it might be worth for me to check to ensure continuity. I don't think/know that there is a separate filter besides what is in the tank on the pump... I'll check and replace if so. I'll also do the pressure test.

The vehicle is long in the tooth, body gone and interior... well, lets just say NO ONE will ride in it. Then again, no one would ever steal it hehe. Pee eww! But, it does what it needs and sadly, I've poured a lot of money into it recently. I'll respond back with what I find.

Thanks again.

B.E.F.

GrtLksMarlin

I was finally able to get those tests done, here are the results;

Codes thrown are:
P0443: P0443 (M) Evap Purge Solenoid Circuit An open or shorted condition detected in the EVAP purge solenoid control circuit.
P0645: P0645 A/C Clutch Relay Circuit An open or shorted condition detected in the A/C clutch relay control circuit.
**One version of testing threw one code and the other threw a different one:
**P0700: P0700 EATX Controller DTC Present This SBEC III or JTEC DTC indicates that the EATX or Asin controller has an active fault and has illuminated the MIL via a CCD (EATX) or SCI (Aisin) message. The specific fault must be acquired from the EATX via CCD or from the Aisin via ISO-9141.
**P0705: (no code list remark, this is from unit): Transmission Range Sensor Circuit
P1491: P1491 Rad Fan Control Relay Circuit An open or shorted condition detected in the radiator fan control relay control circuit. This includes PWM solid state relays.

Fuel system test performed from manual;
Pressure Test (running): Cold, roughly 48-psi., after running till at operating temp., at idle the needle bounces between 40-50. Even minimal throttle steadies the needle at 48.
Capacity test: Less than the 1/4-liter/7-seconds noted in the manual. Perhaps 1/8+/-
Leak Down Test: bleeds down in 'pulses' from 48psi at pump start to roughly 5psi.
Time to reach pressure 48 psi: 1-2 seconds, pump shuts off (as it should) then pulses down steadily.

I did not perform relay, pump amperage draw or injector tests.

Here's the odd (usual BS) thing. Whereas before the vehicle would run/drive perhaps 2 miles over 4/5 minutes, when testing it ran for a solid 30 minutes, with throttle boosts on occasion. So, I drove it up and down the road perhaps a mile, still it didn't die. During all of it i left the fuel gauge connected and watched it. It continued to flutter through first gear, yet when it shifted to second the needle stabilized at roughly 48 psi. 1st gear it bounced between 40-50 continuously and rapidly.

So, uh, duh... now what? Any ideas?

B.E.F.

GrtLksMarlin

@PatHenry ; just to get back with you after your help, I ended up fixing all of the issues (most of the codes were thrown due to the absence of a fuse. The owners manual conflicted with the service manual). In any case, with little else left i went ahead and replaced the fill tube and the pump. Unfortunately, 190k miles of rust meant the bolts for the hitch, armor, and likely tank straps were going nowhere. So, I ended up using a post on this site: https://www.cherokeeforum.com/f2/fue...2/#post3231679 to cut a hole through the floor and access the pump. It worked like a charm, and gave me a chance to fill some of those holes up into the cabin behind the quarter trim.

All's good now...except I think the steering linkage needs some attention. In my opinion, this old girl want me to grant her the rest she deserves, but until the big kaboom, I'll keep at her.

Thanks for the help,

B.E.F.

PatHenry

Hahahaha - Well done!!!

You are mistaken though... the old girl is saying "You like how that fuel work made the motor purr..... now for less than a couple hundred bucks you could have a brand new steering linkage and get nice tight responsive steering too... "

Be warned, though, after that it will be, "imagine how nice a new set of shocks and leaf springs would feel"... "wouldn't it be nice to have no more oil spots on the ground when you park".... "isn't it time for a tune up.. C'mon, champion copper plugs are cheap!".... and so on.