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  #1  
Old January 19th, 2019, 23:58
dudeinthepnw dudeinthepnw is offline
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Need help - Long cranking issue has turned into not wanting to run issue

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 shits 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).
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  #2  
Old January 20th, 2019, 08:13
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ehall ehall is offline
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Re: Need help - Long cranking issue has turned into not wanting to run issue

most likely the fuel pump
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Old January 20th, 2019, 08:52
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Re: Need help - Long cranking issue has turned into not wanting to run issue

Add another vote for fuel pump.

That filter that was so bad probably contributed to its demise. Having to work extra hard to get past the filter doesn't help a pump out in the long run.

It is not that hard to swap a new pump into the old sending unit assembly. As long as your fuel gauge has been behaving I would not bother to spend the extra money for a new complete assembly. Odds are good your original was built better than the replacement.
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Old January 20th, 2019, 11:15
dudeinthepnw dudeinthepnw is offline
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Re: Need help - Long cranking issue has turned into not wanting to run issue

Thanks for the reassurance guys. Appreciate it.
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  #5  
Old January 20th, 2019, 11:59
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tjmotter tjmotter is offline
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Re: Need help - Long cranking issue has turned into not wanting to run issue

This is the one I used on my '90 XJ. While I don't recommend many 3rd party pumps, Delphi has always worked well for me:


https://www.summitracing.com/parts/d...okee/year/1990


Not sure which version will fit a '95 but places like Jegs and Summit should offer quality replacements like Delphi.

Last edited by tjmotter; January 20th, 2019 at 12:03.
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  #6  
Old January 20th, 2019, 13:46
dudeinthepnw dudeinthepnw is offline
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Re: Need help - Long cranking issue has turned into not wanting to run issue

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.
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Old January 20th, 2019, 14:00
lawsoncl lawsoncl is offline
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Re: Need help - Long cranking issue has turned into not wanting to run issue

Figuring out if you're losing spark or fuel pressure, or both would make diagnosis much easier. The hard start and failing once it warms up is symptomatic of a bad crank sensor. Could be a a bunch of things like a bad autoshutdown relay, bellhousing bolts are loose, etc.
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Old January 20th, 2019, 14:08
dudeinthepnw dudeinthepnw is offline
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Re: Need help - Long cranking issue has turned into not wanting to run issue

Definitely don't think it's the bellhousing being loose. I read about the ASD somewhere else I think yesterday. Since it's a relay, wouldn't it just "not work" like other relays typically do when going bad?

I've gone to thinking it was the FP, but my inclinations are leaning towards the CPS now. But again, just wish I had a couple more diagnostic tools readily available to me so I could test things more in depth. I appreciate everyone here trying to lend a virtual hand.
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Old January 20th, 2019, 18:40
GreaseMonkey17 GreaseMonkey17 is offline
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Re: Need help - Long cranking issue has turned into not wanting to run issue

You need to check fuel pressure with a gauge . A fuel pump will go bad when hot then sometimes fire up when cold until it acts up again . It’s not going to be an identical situation each time it acts up .
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Old January 20th, 2019, 18:58
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Re: Need help - Long cranking issue has turned into not wanting to run issue

Sounds like what my 96 did when the CPS went, right down to dieing in an intersection in a foot of snow.

But when my front O2 sensor died, it would start to miss/lurch after a couple of minutes of driving and would eventually do much the same thing as a bad CPS.

Have you checked the key/MIL codes? The CPS or the O2 sensor may not through a code. But if they do, it is often way late and the sensor has almost totally failed.

CPS can be funny, in that the computer can compensate when it misses a beat or two. But if it is right at the point where sometimes it misses a few too many beats for the computer to compensate, it fails completely.

And always remember the power in for the CPS is shared by other sensors. What appears to be a failed CPS may be a failed cam position sensor or even a wiring problem.
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Old January 20th, 2019, 21:39
dudeinthepnw dudeinthepnw is offline
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Re: Need help - Long cranking issue has turned into not wanting to run issue

I've checked the codes multiple times (OBD1 obviously).

The only code that has ever displayed is 55 which just tells me that there are no dtc's stored lol.
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Old January 20th, 2019, 21:40
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ehall ehall is offline
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Re: Need help - Long cranking issue has turned into not wanting to run issue

What you're seeing is symptomatic of low pump pressure

Normal operation the pump puts out a constant rate of say ~100 PSI. As the RPMs go up and down the consumption of fuel in the rail varies. Meanwhile he regulator keeps the rail pressure at a constant ~40 PSI (or whatever is appropriate for your year) as consumption varies. But when the pump starts to die its constant pressure starts to drop off, maybe down to something like 50-60 PSI, and as consumption increases the pressure drops to below the regulator baseline, ie starvation.

Symptoms can also manifest from a bad ignition coil, but fuel pump is more common and if you are already having issues with fuel that makes it more likely. Neither of them will produce codes except possibly misfire

Pressure test gauge on the rail and on the line between the pump and regulator is the only way you will know if the pump is actually failing
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Old January 20th, 2019, 21:59
dudeinthepnw dudeinthepnw is offline
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Re: Need help - Long cranking issue has turned into not wanting to run issue

Thanks, I'll go rent or buy a FP gauge tomorrow.. Wish I still had mine. I feel like for peace of mind I should just do the pump and CPS lol.

Does anyone have a recommended aftermarket pump? If I replace it, I don't want to do it again 6 months later. I've seen bosch and delphi be praised more than the other auto house specials.
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Old January 20th, 2019, 22:27
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Anak Anak is offline
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Re: Need help - Long cranking issue has turned into not wanting to run issue

Bosch would be (and was) my first choice.

I don't have any issues with Delph though (running that in my "burb).

Avoid Airtex. I have seen a number of complaints about theirs.
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Old January 20th, 2019, 23:33
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lazyxj lazyxj is offline
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Re: Need help - Long cranking issue has turned into not wanting to run issue

Fuel pump pressure gauges are cheap, without one, you are only guessing if the fuel pump is working properly. It's a 'must have' diagnostic tool.
https://www.harborfreight.com/fuel-i...ter-62623.html
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