dudeinthepnw

I'll try to keep this fairly short. A couple weeks ago, my 95 XJ 4.0/Auto started developing the fairly common long crank issue. It was mildy annoying at first, but I would always be able to get it started and get to where I needed to be.

Slowly it got harder and harder to crank and fire. I was picking my son up from his mom's work a few nights ago and I cranked on it for so long that the battery died (Battery is less than a month old FYI). My GF came to jump me and the Jeep started up and I drove home without issue.

The following day, I replaced the fuel filter (which looked like it had never been done), I replaced the plugs/wires (champion copper .035 gap) and replaced the rear pcv valve because it was cracked.

After finishing those up, the jeep fired right up, idled smooth and seemed to be good to go. I was pretty happy and was attributing the fuel filter with the most credit. I put 50-60 miles on it after doing those things and it was running great and firing up on the first crank too which was making me pretty happy.

Then, yesterday on my way home with my 7 year old son, we were stopped at a light. The Jeep sputtered, I tried bringing the rpm's up and it died. Stuck in the middle of an intersection, I was unable to get it restarted. Naturally it was raining and cold. A nice gentleman and his wife stopped to help. He and I ended up pushing the jeep nearly half a mile to a parking lot. Again it was cold and pouring rain, not to mention the road was just barely uphill enough to make it a completely defeating experience. Finally got into the parking lot and I started going over the basics. Double checked everything I did the previous day. Made sure I didn't leave a fuel line loose, checked the plugs/wires/coil wire, checked for obvious vacuum leaks etc.

Luckily, I had a tarp and some rope in the jeep, so I macgyvered myself a little bit of a shelter to at least keep me partially out of the downpour while I tried to figure out what the deal was.

Sometimes I would be able to get it to fire up, sometimes it would idle for a minute but then sputter and die. Sometimes I would be able to hold the rpms up at 2-3k for a minute, but it would again do the same.

For ****s and giggles, I was getting frustrated, my kid was cranky and cold, so I summoned an uber who took me to oreilly, I picked up a new coil and replaced it. Fired it up, it idled, seemed relatively smooth. I became cautiously optimistic. And then it died again. After spending about 3 hours in the freezing rain of a retail parking lot I traded in my mancard and bestowed a tow truck to come rescue us from the grips of hell.

Got the Jeep home, let it sit over night. Went out this morning, fired it up, idled for a minute, then died. Got it started again, was able to actually move it under it's own power to a different parking spot that has tree cover (apartments, yay). I pulled the throttle body off, clean the TB, cleaned the IAC, and further inspected for any pesky vacuum leaks. Nada. Same thing.

My inclination at this point is most likely the fuel pump is weak. I don't have a fuel pressure gauge and no friends nearby to shuffle me back and forth to the auto parts store. I've been looking at pumps online and I would really prefer to replace the entire assembly if I'm going to do it, but it doesn't seem to be an option. The common thing seems to just be the replacement pump itself. If anyone could point me to a link of a fuel pump assembly that would be great. I found one that was like $500, no thanks lol.

FPR is the other thing I wanted to test, but couldn't get it to stay running long enough to pull the vacuum line off and check for differences.

Sorry for the novel. I need my XJ brothers (and sisters) to tell me I'm missing something stupid here. It's my only rig at the moment and I gotta be able to get my kid to school and all that fun stuff. It's crunch time tomorrow (which thankfully looks dry weather wise).

msumms

fuel pressure gauge is free to rent with your credit card at oreillys. i just rented one this weekend. verify pressure. then check cps. could order cps on amazon and return it if it's not the cps (make sure you're buying it from AMAZON not from a different vendor thru amazon). try mopar. could even go to the dealer. buy it, keep it clean. see if it fixes the issue. if it doesn't you could just return it. others more experienced will chime in with better ideas. slow down, breathe, it's gonna take some time and taking an uber here or there might be worth it to save you from stress and anxiety. sorry that this is your only rig, hope you can clear it up soon.

tjwalker

While it could be a number of things, the #1 suspect is fuel.

I'd test it to be sure though as testing is the only way to know for sure. Testing fuel pressure is the first thing any technician would do if you had it in their shop. As already mentioned, many parts stores will rent you a fuel pressure gauge kit inexpensively. Call around for availability.

If fuel pressure tests okay (31 psi is needed for your vintage to run), then next up to test is spark. You could test for that first if you like. Pull a plug, keep it attached to the plug wire. Place the plug electrode near a good engine ground with an insulated pliers, have a buddy crank the engine while you watch. You are looking for a strong, blue, snapping spark.

Good luck and keep us updated!

jordan96xj

Just to press the point home, since the problem can be reproduced, the first step is to see the fuel pressure while the problem happens, this can rule in/out some pretty important items.

In my opinion, a vehicle that starts fine - then runs for a minute or two - then starts sputtering and dies is not likely to be the fuel pump. Could be, but I think there are more likely suspects. Like an upstream O2 sensor that is failed and telling the computer that it is full rich or full lean, causing the computer to adjust the air/fuel ratio out of wack. When the vehicle first starts, it doesn't use the O2 sensor for these calculations, so the mixture is based off some basic preset values. So it runs. If the vehicle idles a little longer without problems on the first start of the day, but subsequent start attempts have an even shorter idle time before the problem begins, I would be even more inclined to question the O2 sensor. Because the O2 sensor comes into play quite a bit quicker on warm starts (about 30 seconds vs. about 1.5 minutes on a truly cold start). I think you can find the upstream O2 sensor and disconnect it, then try starting and see if it stays running longer. The computer will throw a check engine light, but it will have no choice but to run off the preset values - and won't be able to take the O2 sensor values into account for mixture decisions.

dudeinthepnw

The 02 Sensor is something that I hadn't given much thought to be honest. Makes sense though too because the "first start" is running in closed loop, once it reaches operating temp it goes open loop and starts reading info from the sensors.

So here is the general update from this morning:

Okay, so I'm a bit confused at this point. I went back out this morning to poke around a little more before committing to the fuel pump. It started right up after sitting all night. I let it sit and idle for about 10 minutes and there wasn't even a hiccup.

While it was running, I spent time again under the hood checking for any lose connections, any particular wire/sensor plug that would cause the engine to react somehow. Didn't get any response from anything.

I thought I would back it up and drive a little just back and forth by my apartment to see how it did. Backed up ~50ft, drove forward, backed up again, drove forward - this time giving it a little gas, enough to chirp the tires in fact (wet pavement). Then it slowly started sputtering before dying again. Attempted to restart and no luck so I started trying to push it back into the parking spot (slightly uphill again as usual lol). I was struggling to push it by myself up the incline so I tried again to start it and it fired up and then died. Tried again, fired up and was then able to drive it forwards to the parking spot.

Again, left it running, and it seemed to idle fine. I could rev the engine under the hood as much as I wanted to (throttle body), I'd rev to 3-4k'ish and then let go of it abruptly to see if the engine would recover without stalling, which it did.

I'd kill it a couple times and it would fire right back up.

I would think if it was the fuel pump that it would break up/sound like crap when revving to 3-4k rpm. Maybe it is the dreaded CPS after all?

I'm pretty mechanically inclined, I can replace just about anything that it may end up being, but the problem is when I moved into my apartment after my ex wife and I split up, I went from a garage full of tools and equipment to basically just having the basics. I don't even have a multimeter right now. I have no friends or family nearby that can lend me a car or run me to the auto parts store etc right now and I have my 7 year old son with me. I'm hoping hoping hoping that my XJ brothers can lead me to that smoking gun if you will.

I get optimistic when it fires right up and seems to idle indefinitely just fine, but I sure don't trust it for obvious reasons. Man, the only other time the Jeep has left me hanging was just when the starter crapped out and I was able to get a starter and replace that in a parking lot in like 10 minutes. This is the first "gremlin" she's given me.

dudeinthepnw

Also just as a briefer: Work done to the jeep within the last 2 months - New battery, New starter both about 8 weeks old. Within the last few days, plugs (champion copper .035), wires, coil, pcv valve.

I also wonder why after I did the plugs/wires/pcv valve that for nearly two days, the long cranking issue was gone, it fired right up, and ran great until the subsequent issues arouse again.

dudeinthepnw

Today's update:

Well, took a gamble today - drove it to work this morning. Got there no issue. Went to pick up my son from his moms house after work. When leaving work, it fired right up, first crank. His moms house is about 8 miles away. I made it literally to the 1/2 mile sign from her exit and it started to sputter, lose power and died on me. I was able to put it in neutral and coast on the shoulder with my hazards on all the way to the beginning of the off ramp.

Tried for several minutes to restart it and it wouldn't. Finally after a feathering the gas about 1/2 throttle while cranking it, it fired up. I was able to drive the final mile or so to his moms house. Left the Jeep running while I went in to get him. Came back out and it had stalled. Crap.

Tried various things to try starting again to no avail. She has AAA and was nice enough (for an ex wife lol) to let me use it for a free tow. While awaiting the tow truck to arrive, I kept playing around with the Jeep. I pulled the fuel pump relay, noticed a little bit of darkened discoloration near the top of one of the terminals (prongs?), it looked like the slight discoloration of when metal gets hot.

I pulled the AC Relay and swapped the FP relay. In doing so, I also sprayed some wire dryer on the relays and the fuse block itself. Put the relays in, and the Jeep fired right up. So now I'm wondering "is it just a relay" or "is it just a coincidence?" Let it idle for a few, then started driving a few laps around her apartments, seemed fine. Parked again, turned it off. Waited a minute and tried to start it again. Fired right up. Hm.

The tow truck had already been summoned, I let the Jeep run for close to 20 minutes. The tow truck shows up. Wasn't a flatbed. I was hoping for a flatbed tow, but shrug. Start talking to the driver, told him I got it running and that it's been running fine for 15-20 minutes before he got there but that I also still didn't trust it. As we are talking to each other and contemplating that I attempt to drive it home and call them back out if needed, I walk towards the Jeep and it had died again and refused to restart again.

Alright, screw it. Took the tow truck ride home again. Still never got my hands on a fuel pressure gauge today. I was going to do that on the way home.

Also I noticed before I swapped the relays, I couldn't hear the pump prime when turning the ignition on. After swapping the relays, I turned the key on and I could hear the pump priming again so I figured that it would start after that and it did.

I want to believe so bad that it's just the fuel pump and that I should just replace it, but I also have this sneaky intuition in the back of my head telling me that it's something related to the pump but the pump isn't the actual issue. I could be wrong though of course.

The under hood fuse/relay box has a small piece of the cover that has been broken off since I bought the Jeep. Possibility that because of this it has allowed moisture/condensation to build within the fuse/relay box and that could be the cause for the recent problems? I'm probably stretching here, but it wouldn't be the first time that I've had something wrong and I started by replacing the obvious/big/common/expensive parts first only to find out later that it was a bad ground/stupid problem elsewhere that was causing the other component to fail or intermittently fail.

jordan96xj

When it fails to start, you should be testing to see if spark is present. That would be job #1.

If spark is present, then you should be testing to see if fuel is being delivered (starter fluid sprayed in the throttle body). That would be job #2.

I can tell you are stressed, but guessing and hoping won't get it fixed. Diagnosing, identifying, and fixing will.

You can do it, let's move forward.

PatHenry

I agree with Jordan.

What I would do is go out and get everything you're going to need together - Fuel pressure gauge, starting fluid, multi-meter, electric contact/connection cleaner, insulated pliers, etc. and be ready to diagnose.

If you haven't cleaned up the ground in the cargo area behind the spare tire and trim panel, do that right away. The fuel pump grounds to that location and a spotty ground there will drive you nuts.... in other words, it's one of the gremlins' favorite hiding spots.
I would also clean up the connection to the coil, CPS, fuel pump and fuel pump relay ASAP. Worst case scenario - you performed some routine maintenance that needed to be done anyway.

dudeinthepnw

Welllll...

This afternoon, I went out to start the jeep. It fired right up as it usually does when cold/sitting for a long time -even with the problems it's been having lately. I let it idle for about 20 minutes, came back outside, popped the hood and started poking around.

Something in the back of my head kept telling me that the problem is not what it seems, it has been acting like the fuel pump has been on it's last leg or like the CPS is getting wacky and I actually ordered both parts last night just so I would have them. But I wanted to continue ruling other things out. So I'm inspecting the CPS wiring/plug again, fiddling around with the PCM seeing if any sort of movement to the PCM of wiring had any effect, I'm double checking all the grounds again so on and so forth.

I came around to the passenger side, and since just 4 or 5 days ago, I had replaced the plugs/wires etc I was double checking all that again etc. The day I did the plugs/wires I noticed the Jeep was literally running better than I think it ever has since I owned it. That lasted for about a day and half and since then I've been chasing this "gremlin".

I noticed that the #3 cylinder had coolant sitting in the spark plug hole. "That's odd, I thought", and then I noticed that one of the 5/8" heater hoses that runs along the top of the valve cover was leaking. Hmm. It wasn't spraying like fountain, but it was definitely leaking. Essentially in the line of fire from this leak are the #3 and #4 cylinder plugs/plug holes, the distributor and the ignition coil.

I killed the engine, cleaned everything up on that side of the engine as best as I could, pull the plug wires out to dry the holes, and I left it like that for now until I can go get a new heater hose...So at this point, I'm almost thinking that all of these issues I've had recently could seriously be cause by a $2 piece of hose, because "in theory", if it's leaking onto the plugs/wires/distributor and/or coil it will most definitely start running like crap once those components get wet enough.

I still can't say for certain that this silly hose is going to be the end all/be all solution to the random stalling/dying, being really hard to start after it's been running/driving for a while etc. But I definitely feel optimistic at this point. So I'm going to replace the hose, grab 2 new plugs again for 3 and 4 and going to replace the cap/rotor this time as well since I should have done that with the plugs/wires anyways the other day.

That's all for today's update lol.

DCWinterXJ

I am curious to see how you made out after the hose repair and air drying....Is she back up to speed? I would just like to know the end result. Usually a lack of responses means you solved the problem or gave up and joined greenpeace. Hey whatever works. But I hope everything is good brother!

dudeinthepnw

Sorry I haven't updated! I thought the issue had been resolved. It showed it's face again though - After it stalled on me again, I went ahead and replaced the Crank Sensor - After getting the new CPS in, it was running great again, nice and smooth, idle'd for as long as I wanted, could drive around and make multiple stops etc and it would always restart and it seemed like the infamous CPS had struck again and I was good to go.

Fast forward to today, left to go pick up my son. I met them at his mom's work which is about 15 miles from home. Jeep ran fine the whole way there, I was almost to her work and I started getting a bad vibration from the front end. I got to her work and crawled underneath while waiting for her. The front u-joint took a dump - So I figured screw it, I'll just pull the front drive shaft on and fix it later, I don't need 4wd to drive home. Then one of the bolts snapped, then another bolt had already been rounded off from the previous owner. So after fighting with something that should have taken 5 minutes for 45 minutes, I finally got it out and we were on our way.

Got literally less than a mile down the road and it did it again! I couldn't help but laugh. I was able to coast into a parking lot this time which was nice, didn't have to push it half a mile in the rain. The difference this time compared to other times it stalled on me is that I actually had a fuel pressure gauge with me this time! So I hook up the gauge and work on getting it started. I get it to fire up briefly, idled for a moment then sputtered and died. The fuel pressure never cracked 20psi while it was running. Any attempt to "Save it" by giving it a little throttle would result in small backfires before dying. Well, that also seem to correspond with fuel level. In retrospect it looked like when it would run okay for a day or two at a time, I had at least half tank of gas, when the stalling issues seem to show up, it seems to have a pattern of being at 1/4 tank or lower. Hypothetically, that would tell me I can just keep a full tank in it and be okay, but I don't trust that idea. I'll be replacing the fuel pump tomorrow. Also have a new FPR that I ordered and will be here tomorrow as well.

FWIW, ended up having it towed home again. (Thank god for AAA (Thanks mom!)) lol - So between the u-joint and the broken/stripped bolts pulling the front drive shaft out, and the whole stalling/getting towed home again crap, it's made for a long night again.

On the plus side, assuming the fuel pump is indeed the actual source of this issue and a new pump fixes it, I will feel pretty good about things. In the past couple weeks, I've done plugs/wires/cap/rotor/coil/fuel filter/cps, cleaned the IAC, replaced the leaking valve cover gasket with that beautiful beautiful fel-pro. I've done valve cover gaskets on a lot of cars over the years, that $40 fel-pro was worth the money. But yeah, got that all cleaned up/sprayed a fresh coat of black paint on the valve cover while it was off, replaced all the heater hoses, a lot of vacuum lines (still have a few to replace). Under the hood is starting to look 10x better than when I got it a year ago.

Anyways - let's make a prayer to the XJ gods that the fuel pump will be the end of this headache. (Also replaced the ASD/Fuel pump relays for good measure).

Picture for fun - the day I replaced the CPS the weather was terrible. I was terrified when I saw the apartment office management, thought they would throw a **** fit but they were super cool about it and just felt bad that I was out there fighting the freezing rain and wind to get it fixed. (Oh, one last side note - For those that have never replaced the CPS - Pull the front drive shaft out, when I did that earlier and looked up I was amazed by how accessible the CPS was. Wish I had done that when I replaced it lol)

BillyBoy

X2. Nice message J.

gat

Did dropping the tank help? I had a problem with a fuel pump that was not fully connected to the rubber tube. Some flow would go into the tube and some flow would spew back out of it. Having a full tank would inhibit backward flow. I'm real curious whether you were having a similiar situation instead of just the pump itself starting to fail.

dudeinthepnw

I didn't drop the tank, I'm thankful for the side mounted pumps lol - Process wasn't too bad.

Pulled out the well known to be crap airtex special that the previous owner had put in and replaced it with an OEM Bosch.

So far, so good - but it's fooled me before so I reserving my optimism until I'm certain it won't start acting up again. But to be honest, the engine almost seemed quieter with the new pump, ran smoother etc. I have left the fuel pressure gauge hooked up while I drive for now so I can keep an eye on it, but the pressure has been rock solid with the new pump so far.