I'm on a cross country move from New England to Reno. I have a 99 XJ 4.0 with only 89k miles with a 3.5" RE lift, 31" x 10.5" AT bfg's, and am fairly loaded plus towing 2 motorcycles in a 6'x10' enclosed trailer (about 2500 lbs). I've been running in 3rd all day at about 60 mph on the highway and haven't had any problems. Engine temp is good, fluid levels are all good, had a recent inspection and tune-up and all is good. Not running the AC either. Jeep ran great all day until the engine suddenly quit on the highway. I immediately pulled over and checked for signs of anything. No smoke, no check engine light, no leaks and all gauges and fluid levels looked normal. Tried to restart and it fired but wouldn't turn over. Waited a bit (maybe 5-10 minutes) and tried again and it started right up. Let it idle for a few minutes and revved the engine a couple times and everything seemed normal; no stumbling or anything. Got up to speed and pulled back onto the road and made it about a tenth of a mile before the engine quit instantly again. At this point I called my roadside assistance provider and they towed it and the trailer to a nearby garage that is typically open on Sundays. Unfortunately, there was a sign on the door stating that they would be closed 8/29 for a company function so it looks like I may be stuck here in Ohio until Monday. Now I'm back in a shady motel and surfing the internet trying to find out what may be the problem. I initially thought it may be a clogged fuel filter because the vehicle has been hardly used in the last 2 years and earlier this morning I ran it down until the low fuel light came on before I found a gas station. After refueling, it ran great for several hours after that until the engine suddenly quit. I've read several threads about faulty CPSs but am not sure that is a likely cause.

The Jeep is currently sitting in a lot at a repair shop about 1/2 mile from here but I still have the keys. I'm wondering if there is a possible DIY repair that could be made or if I should just hold out until Monday to have the mechanics look at it and loose another day. Does anyone have a similar experience and solution or any insight into what might be the issue?

 

could be alot of things that would cause this erratic operation. being that u are traveling ur stuck with what services are avail. things i would check would be spark,fuel, maybe pull a plug? kind of limited working in a repair shops parking lot by urself. might have to wait for monday instead of throwing parts at it. sorry for your luck but could be something cheap but finding that out on the road sucks!!!

 

Check for spark, could be the Crank sensor crapping out on you.

 

forgot to say that fuel filter is part of the fuel sender in tank 96 & up. i wouldnt wana drop tank in parking lot unless i was for sure that it was bad!!!

 

Yeah, all good points. I realize I'm pretty much SOL until Monday but being in a foreign land (to me at least) and dealing with random mechanics, I figure it wouldn't hurt to find out as much as possible about the possible causes. Realistically, there isn't much I can do in the parking lot with limited tools so I am probably better off to just wait it out rather than start throwing money at it, but I figure it is worth hearing what others might have to say. Thanks for the feedback.

 

I don't think it would restart if it was the CPS...I believe it would spit and spudder if it was a fuel issue...I would pull a plug, it could be a distributor going bad. ( I think '99 still had a distributor ) Good luck and let us know what it is!

 

I just walked over to the service station where my jeep is parked, waiting to be serviced tomorrow (hopefully). It is extremely hot & humid out so I am not sure if that plays a role, but I tried to start the jeep 3 times and each time the starter cranked but it would never turn over. I couldn't get it started. Given this additional info, does this change any of your suggestions? From all the threads I've been reading and from my own experience this seems indicative of a failing fuel pump, correct?

 

Turn the key to "On" and you should hear the fuel pump energize (1½ second hum at the back). If not check the relay and fuses but it sounds like a failing pump (since it seems to have gotten worse) or a clogged filter. A final check with a little gas in the throttle body would tell you if it's just fuel deprived. Sounds like you're on the right track.

 

if it is a failing pump sometimes not always you can beat on the bottom of the tank and the pump will work for just a min or so, if you do that and you hear it kick on and it starts then that tells you its a pump, another would be a crank sensor, i would start with those two things, sry about your luck i had it happen before but only about a hr out from home

 

Shoot some starting fluid into the throttle body, if it fires, then you have a fuel problem. No fire means you got a spark issue.

 

Thought I was going to be closing the book on this one today but surprise surprise...

I got a call from the shop first thing this morning and it turns out there was no spark so they swapped in a new ignition coil and I was good to go. Back out on the highway and cruising. A short 362 miles later and the engine just died again and I coasted to a stop along side the interstate. Once again I was on the phone calling for a tow for the second time in 3 days. When the flatbed arrived, I explained the story to the driver and we checked the ignition coil for spark and once again, it was dead. The grounds were good and the wires were all in good shape too, they weren't shorting out anywhere. Fortunately, he towed me to an Autozone and I picked up a new coil and installed it in the parking lot while the Jeep was still loaded on the flatbed. Sure enough, it fired right up.

So is it a coincidence that the ignition coil the service station installed this morning was faulty, causing it to die after just 362 miles?? Or is there a bigger problem that will ultimately kill this new ignition coil in the next few hundred miles as well?

On the bright side, I have finally made it half way across the country... but I should have been in Reno 3 days ago. Any insight would be appreciated.

 

If it dies again, get it warrantied out then start tracing your harness. Sometimes wires can chaff and ground out. And since it was parked for about 2 years maybe a little critter made its home. But look at electrical, the basics being wiring. Glad you made it there safely. Reno is not a bad place. i grew up in norcal and have ALOT of friends in sparks/reno area. I visit often, if it is still doing wierd stuff, next time i am out there i can do my best to help you out.

 

I bet you a dollar it dies again, and when it does, just replace the crank sensor and be done with it. Ignition coils do not fail very often anymore.

 

how would a crank sensor be killing a ignition coil?

 

This is one I want to know, too.

Coils are hard to kill...gettting a crap one from an autoparts store is easy to do.

I'd get a warrantied coil and throw it in there...and buy a spare for the glovebox - you can always return it unused - and that will give you time to debug.