Mott

So i was driving to work today going about 70 when my jeep died,gauges drop and engines off, scares the **** out of me considering im going pretty fast,then as im pulling off the highway onto the shoulder it turns back on.Then as i keep driving on my way to work i notice my rpms jump from 2500 to 3000 then back down to 2500 and so on and so fourth, and when it jumps up to 3000 i feel the engine lose power then get it back when it drops down to 2500.Still not done yet, as im stopped at light,keep in mind im stopped uphill,it just shuts off on me. I put it into park and start it back up and just go back on my way to work. I have no idea what this could be... I was thinking my throttle but i dont know what that would have to do with it turning off on me, a few times in the past month or so, if i floored it,it would stall and id let off the gas and would come back alive. Also if i tilt my steering wheel up it turns off. My dad said its probably something electrical and said i should get it looked at sooner rather then later. Figured id share this with everyone and see what you guys think. Any help is greatly appreciated.

tjwalker

Could be the crankshaft position sensor starting to fail. Here is a link to a good thread on it. The crank sensor is a VERY common sensor fail on the 4.0 XJ.

Another possibility is the ignition coil, but the crank sensor fails more than the coil.

http://www.jeepforum.com/forum/f11/c...ailing-639123/

MATT 87 CHEROKEE

Bump

tampaviking

My cps did this to me, but it was just coming loose. I would suggest disconnecting it and cleaning it before replacing.

MATT 87 CHEROKEE

Same here... I'm still wondering if I should replace it though

bigA

Replacing it might be good for "peace of mind". I sometimes replace parts like that according to age/milliage. I mean stuff like batteries, hoses, etc. If you suspect the CPS, maybe it's a good time to change it.

tjwalker

I don't disagree with this. Intermittent problems can turn into a catastrophic one which can leave you stranded and in need of a tow.

I buy my crank sensors directly from Jeep. I have had mixed (poor) luck with aftermarket crank sensors.

lurk520

I also have a random stall problem that seems to be electrical, in fact it happened to me today. When it happens my radio station memory is completely wiped out as well, indicating the Jeep lost all power, as if I disconnected the battery. Then it will crank and kick over but won't stay running, also my gauges get all wacky, the fuel gauge pings on empty even though the tank is full, but after about 20 mins it fires right up and drives fine. Could this be CPS? Would a faulty CPS cause my Jeep to lose all electrical power and wipe out my radio stations. I'd really love to figure this out. I've had it in the shop a couple times and they can't diagnose it.

MATT 87 CHEROKEE

Bump

cpnwrench

this is no B.S....am reading everyone's post. My beast has failed one way or another over the years, and I still love it.... Yes, the CPS is the first thing I would REPLACE. period. IF.......it still has this problem......this is weird but it happened to me.....

the fusebox wiring harness in the engine compartment. i used a meter and found the 12v power wire for the engine fuse in the fusebox had actually wiggled loose over the years and i had to disassemble the fusebox and re crimp several of the input leads to the bottom of the fusebox....

it solved the "mysterious" stall.......


hope it helps!!



cpnwrench

TheJerm

That sounds like a bad ground or loose wire

tampaviking

It's ridiculous just how important the grounds are on these engines.

lurk520

Where are the grounds I need to check? How many are there? What components do they run to? It's kinda weird though how after it sits for a while it will start back up and run fine. Almost seems temperature related. Not sure though, there aren't any solid consistencies.

Ninja Falco

Battery terminals need to be cleaned?