Went wheeling the other day in some diff high snow, with lots of hills. Jeep was running fine till I ran up the next hill to play cameraman and got back Jeep had stalled. hard to start, like it was flooding. Finally got it going and sounded like a plug wire had come off and that cylinder wasnt firing. So checked wires and all is well, we decide to limp it off the trail. So we turn around, I get up the next hill with that gutless thing and it starts running fine. So we decide we should still head home anyway and the downhill coming in is the steepest yet, I cant make it up so I got to pull cable. Start pulling cable and she starts sputtering, im sliding down the hill wanting to keep it running for fear it wont start again, and I didnt make it. She died. Hard to start and when it did same thing, not firing on all the cylinders. So we keep it running with lots of throttle to winch me up and then my bros blazer. Soon as im done spooling the cable she coughs and now shes fine. WTF? I cant go out again knowing she might do that, and I got a club run planned for next week!

 

Well you've got 3 things you need to look at: 1.) Spark (or lack there of) 2.) Air (or lack there of) 3.) Fuel (or lack there of) To me, it sounds like a fuel issue. Maybe a fuel pump starting to go bad, or if you're fuel injected, a bad injector. How much fuel was in your tank at that time? Has it been cold and then warmed up? Maybe you've got some water in your tank. Also, check your air box and your filter - making sure nothing is blocking the air intake. Good Luck!

 

Fuel was my first guess. Injectors are brand spanking new, just under a full tank. But why is the crappyness so intermittent? if it was blocked air fuel or spark it would run like crap all the time, right? Im leaning more toward wet electronics at this point, as we were throwing alot of snow climbing those hills.

 

I was thinking of snow blocking the airbox or wet electronics. One thing you can check when it is dark out is arching on the distributor. You may have a loose plug wire distributor side...or, a crank position sensor could be going bad.

 

IM hoping it was water from snow in the distributor. Would a CPS going bad be intermittent like that?
And if it is water in the distributor, how can I stop it from hapening again.

 

I'm new to Jeeps, but not to cars and trucks. I've had a couple of CPS go bad on my vehicles, and 2 out of 3 presented with intermitten stalls/crank no start or extended crank/start. The third one just went bad and the car didn't start. There really isn't anything you can do other than take dielectric grease and apply it to the contact points, then pus the plug wires down as far as they'll go. However, maybe some other members have had this issue or a similar issue and can shed some light on the topic from an "experienced with Jeep" standpoint. lol

 

I as long as your fuel tank was pretty full (not running the pickup dry due to the slope) I would be thinking something electric with an intermittent fault.

I don't have any experience myself as I just got my jeep, but similar to what firsttime 00XJ is saying - when I was quizzing a freind who is a mechanic at the jeep dealership before I bought mine he told me the crank sensor (CPS) was one of the things that ccrapped out on them and that it would probably be worth carrying a spare.

 

Same thing happend to my 98, it started to spudder and lose power, but wouldnt die,

I ended up bringing it to the garage and they worked on it for aweek. It came down to somewhere in the wiring harness or the ECMcomputer, I the computer was brand new. SO i decided to take it from them and messed with the wires and bit and BANG started working. At first I was scared of going places cause it might happened again, but now a year latler its still fine..

 

Mine 93 did that and it was the map sensor. I got a spare if you need one.

 

wet altinator mine ran like poop when crossing a flooded road, and it threw a code for the o2 sensor ran like **** till she dries out then was normal

 

MAP, O2 or my TPS did that when it went bad too.

 

I didn't even think about the MAP or MAF sensors....those will do that too.

 

two things caused that on 90 4.0 (1) coil wire was not all the way into distributer causing a weak spark condition. it would rattle around and cause engine to miss intermittently...run fine for a week...then start missing again. sometimes just a no start...start fine next day w.t.f ?
(2) water in the gas tank ? just a thought

 

It sounds like a fuel thing to me. From what I read it seems like it was only when you were going up the hill's. I had a similar problem turned out to be my fuel filter, going up the hill took more fuel than going down, (going against Gravity) the filter was pretty clogged so i wasn't getting enough fuel to the engine and it was choking the whole time up the hill. (it also didn't want to get going when I would step on the gas on the freeway) probably on of the cheapest fixes suggested so far.

 

I have never changed the fuel filter. Im going to start with that.