Okay I am going to try and keep this as short as possible but, explain what I have done and what codes I have pulled along this journey. 97 XJ, 4.0 with AW4.

Back in March my wife was driving the XJ. She calls me and said that it lost power, jerked like crazy and shut off. She got it started again and made it to my sisters house. When I arrived, I asked her if she tried starting it again, which she said "no". So I hit the switch and it fired up and I drove it the 10 miles back home with no issues. The CEL was on and it was and has been on for quite awhile. I will get to that a little later..
Took the jeep one day about 3 weeks ago to a friends house way back in the mountains. On my way there I felt the Jeep surge, buck and lost power. I knew then that this was the issue that the wife had and then it shut off. Pulled over, hit the switch and it fired right back up. Got on the mountain road to my friends house and along the way it bucked and jerked and backfired nice and loud and shut off. Done this all the way up the mountain. Now, when I went to leave, I started the jeep, idled fine, pulled up to let another friend out and it just shut off but restarted just fine.

Drove it out, no issues, drove it to my friends house, no issues. We pulled the codes and of course I wrote the codes down but, can't find the paper now. But, it was the downstream 02 sensor, coil, and a trans solenoid code. I already had the solenoids ready to go in but, hadn't had the time to do it. So, I decided to go ahead and get all the parts to do a tune up including the coil and CPS because once I popped the dist. cap off and seen all the dried, caked up mud on the CPS, I figured I might as well change it. So a quick search with Rock Auto and all the parts arrived with new 02 sensors, plugs, cap, wires, rotor etc. Changed out all the parts, changed out the solenoids but, I found out that I do not have the downstream 02 sensor. I honestly in the 5 years that I have owned this XJ never knew it didn't have one so this is why the CEL has been on. So all that I changed was the upsteam 02 and left it at that. Drove to work and the issue happened again, bucked, jerked, but this time it stayed running. Made it to work and back home with no issues, but once I hit the driveway, the CEL was on. Pulled the DS 02 again and map sensor code so I bought a new MS and TPS while I was at it and took the TB off and cleaned it along with the IAC before installing the new parts.
Still had the issue so a friend said could it be the fuel pump getting weak and shutting down. So I installed another pump last Friday and got down my driveway and it shut off, no bucking or jerking, just died but, it started right back up. Pulled back up the driveway and shut it off and left it from aggrivation. Saturday I fired it back up and it idled for awhile and shut back off. Then it was hard to start again..Took my spare CPS and put it in and it drove fine that day. Yesterday I went to pick my daughter up, jeep ran fine, took the long way home and it bucked and jerked and shut off. Started back up, made it about 100ft and it shut off and wouldn't start this time. Pulled codes P0351,P0320,P0138 and P0141. Had my dad pull me home with my Dodge and once I got it in the driveway, it started up, ran for a few seconds and died. Went out this morning and fired it up, idled longer but then died again!

I have a fuel pressure gauge coming and I am taking my meter home from work today. Do you folks think that it could be the CPS causing this? I know it isn't a new one but the one that was in it isn't that old.. Sorry this is so long and drug out but, I wanted to give as much information as my old brain can remember..

 

I meant the crank sensor is a used one that I had and the cam sensor is new out of the box.

I have read some posts about the crank sensor could cause this but, I have also read that when it goes bad, it's a no start issue. Mine will start once it sits for awhile but, will shut off!

Replaced:
Plugs
wires
cap
rotor
coil
cam sensor
throttle position sensor
map sensor
fuel pump
cleaned IAC

I will check the crank sensor when I get home with my multi meter.

Anything else I should check? I would like to get it fixed before Big Dogs next month. Thanks

 

Had same issues with daughters 97 ZJ.. Went through nearly the same process and list of parts you did with the addition of 2 CPUs and 3 Crank sensors and 2 batteries.. Over about 12 months, Final fix as suggested by a mechanic was to replace the CPU, TPS and Crank sensor again.. ALL, At the same time, with OEM parts. Previously we would replace an item, what ever the codes suggested, it would work perfectly for 1 day to about 2 weeks, then the issues would come back. Currently it has been flawless for 4+ months now.

 

[QUOTE=PUNISHER;2851947]Pulled codes P0351,P0320,P0138 and P0141.
Do you folks think that it could be the CPS causing this? I know it isn't a new one but the one that was in it isn't that old.. QUOTE]

Generally, when addressing Codes, one should start at the lowest number code and work towards the highest number code.

P0138 and P0141 are downstream O2S faults. First thing to do is check the O2S heaters fuse in the PDC (pic below), then check the condition of the O2S wiring at the downstream O2S. Many times the wiring gets chewed up in the read drive shaft.

P0320 is a CPS code- no CPS signal detected at the PCM. An OEM (dealer) Crankshaft Position Sensor should be used if you plan on replacing the existing sensor. Always examine the related wiring for chafing, and condition (corrosion) of the connector first.]

P0351 is the ignition coil primary circuit. THe coil may be on its way out. But again, check the coil connector pins for corrosion before changing the coil.

98/99 PDC but I think the O2S Heaters fuse is in the same spot on the '97.

 

Thanks guys, I appreciate the help.

CCKen, my downstream O² sensor is MIA. The plug for it is there but no bung in the exhaust for if. I didn't realize it wasn't there till the day the XJ acted up and codes were pulled. I plan on changing the CPS with OEM for sure.

 

I had a similar problem with my 97 XJ dying randomly while driving, and it gave codes for the crank position sensor, cam position sensor, and throttle position sensor amongst others. I replaced the crank sensor three times (after testing with multimeter) then it died and wouldn't start at all. The culprit ended up being a short in the wire to the automatic shutdown relay switch which apparently causes all the sensors to give altered readings.

 

Thanks for the reply. May I ask where you found the short to be located at etc. I had the XJ idling in the driveway Saturday while I was talking to a friend and looking things over. I wiggled, moved, pulled etc. every wire and bundle I could reach and nothing changed. I took it up and down my driveway several times and then it happened. It stumbled and shut off and wouldn't start back up. it cranked fine and stumbled like it wasn't getting fuel. So my overachiever self went in and grabbed a screwdriver to check spark. Not thinking about the wrench flats on the end of the driver (hand gripped firmly) I told my wife to turn it over and WOW!! The XJ fired right and I got the ol' WTF and the screwdriver went flying! I replaced the plug wire and pulled it up my driveway and it was idling just fine. Shut it off and restarted it numerous times.

I am waiting on the CPS to arrive from Mopar online parts and I hope this takes care of the issue..I don't want to show up at Big Dogs with an XJ with known problems..

 

At that point I towed it to my buddy's shop and let him deal with it. I can trouble shoot and replace sensors ok, but I'm no good at chasing electrical problems like that. I started to see a pattern that everything sharing a wiring harness was going bad, told the mechanic the full story, and $200 later it was up and running. That was last year, I just had to replace the O2sensors this week. If only I could find a XJ with no sensors....

 

Punsher, the Crankshaft Position Sensor is located on the bell-housing, reads holes on the flex-plate/flywheel. It's a common cause of random stalls, and generally will not throw I code I believe. (there's all sorts of names for the crank, and cam sensors. One is in the dizy run by the cam, the other senses crank rotation)

In your shoes I'd change it. If you do there are some tricks to make it allot easier.

 

Btw, some post that their gauges act goofy when the CPS is fouling up.

 

My gauges don't work and haven't in the 5 years that I have owned it. I have a manual oil and temp gauge mounted in a pillar pod.

My crank sensor (Mopar) came in yesterday along with a TPS (Mopar) and I am waiting on the IAC and Map sensor to arrive which are also Mopar. Yea, I know, don't throw parts at it but, I will honestly feel better knowing that they are all OEM parts. When they all arrive, I will disconnect the battery and go at it one piece at a time. With my XJ lifted, I can change the crank sensor in about 5 minutes. Thanks for the help and I will let you guys know what I come up with..

 

 

Replaced the crank, IAC, TPS and map sensor/s yestserday. Took the jeep for about a 10 mile ride and another run this morning. No stalling, backfiring or shuttering, it ran great. Getting ready to head out and drive it a friends wedding! Thanks for all the help!

 

Well it didn't last! Was on my way to the wedding when the XJ lost power and backfired. Started it back up, went about 100ft and it happened again! Made it to the wedding but, not sure if I will make it back home.
Not sure what to check now!

 

Beat's me. A couple of years my 90 was acting up. One of the things I tried was to quick turn the key off while it was messing up, then jump right out quick and check the fuel pressure. (that wasn't it, I had sensor wires grounding) The idea of course was to catch an intermitent lack of fuel pressure.