Looking for a little help, my 98 xj has started to act up consistently, it happens either stone cold(first 3 minof driving) or after a 15 min hot soak. You can take off and it falls on its face , sputters, feels like no fuel pressure. Back off the throttle and get back into it and it is fine.....no faults, all tune up stuff good, tps (a month ago) tb cleaned , generally good working order. On a side note a buddy has a 98 zj with exactly the same troubles....
Any ideas?????
Thanks

 

anyone????

 

Have you checked the fuel pressure at the rail? changed the fuel filter?

 

could be your cat. Mine was giving me trouble intermittently.
Brendan

 

Coolant temp sensor could be sending scewed info to the ecm resulting with incorrect pulse width/duration on the injectors

 

Just to add some more info Jeep acted up again, once again no faults logged in pcm. Ohm checked the cps and it failed, replaced no issues for 1 day . Still randomly when cold of after parked for 15 min... map, cts, cmp???

 

For information I found this on another site, What do you guys think????


Mine's Fixed
by D E H - 3/18/09 4:11 PM
In reply to: Now try this by tintinuae
I have not read all the posts on here, but this was my experience.

For what it's worth to anyone, my 98 Cherokee 4.0L was sputtering, bucking (and stalled twice) in the mornings when the engine was cool and on occasion when it was warmed up it would do the same thing on a turn or from a dead stop, but always occurred under a light load (or about 25-40% throttle). I hooked up my scanner one morning for a cold start and recorded the O2 sensors (both) in relation to the throttle positioning sensor and mass air flow sensor. Less than a minute into the drive the bucking/ popping/ sputtering occurred under load. Luckily I looked over to my scanner and saw the O2 sensors were changing from open loop to closed loop (preprogrammed values- to reading the heated O2 sensors input) at that moment. I had attempted to repair this problem by the usual in the posts I’ve read (cleaning PCM connectors, replacing the crank sensor etc...) to no avail. When I saw the erratic O2 sensor reading and saw that it happened when the heated O2 came online I decided it was time to replace the O2 and the heated O2 sensors. Let me preface the outcome with saying that this was one of the most frustrating diagnosis that I have had recently and the fact that the check eng. light NEVER CAME ON ONCE to give me some kind of help, nor was I able to pull any history codes from the PCM.

It's been about 5 or 6 months and I have not had one drivability issue with the Jeep. It drives soooo much smoother, holds it's rpm's longer when shifting providing a much smoother shift and it feels almost new (98,000mi. on the odometer)

Again, take this information as direction, not a sure fix. It might not hurt to print it and give it to a mechanic who has a graphing scanner and some patience.
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Ok ........So I am the only one on the planet that this is happening to??? nice!

Thanks

 

So after reading this thread, it sounds exactly like the issue that I've been having. It started two days ago, and I've been pretty frustrated with it. Changed map sensor, changed plugs and wires all to no avail. The fact that I have no exaust and both the O2 sensors are showing bad, seems like this may be my issue.

 

Well i will have my new sensors tomorrow, I should know pretty soon if it is a fix, it seems to act up every drive cycle now....I'll let you know.....

 

Yeah mine has been every time since is begain, and its getting to the point where I'm getting scared to drive it anywhere. I appreciate the info and ill be awaiting your results lol

 

Mine has been doing that for two years now. Only seems to do it when it gets colder outside. Say 30 deg maybe. It has never left me stranded though. My trouble codes said both o2 sensors were bad. I replaced them, and nothing changed. The check engine light is on. I did notice a while back that my o2 sensor wires that run past the exhaust manifold were touching it. It had burned most of the insulation off and the wires are all exposed and touching. I figured this was the issue. I just haven't got to fixin it. I am curious now to see if it is the issue with other people having the same problem.

 

I have the same issue, but I have changed injecectors and both 02's. Mine started doing this when i changed the Air charge sensor.

 

sounds like what mines doing as well.i'm thinking temp sensor for me(my gauge is not working).i would also like to add,it seems like mine dose it worse when its wet outside...

 

mine is doing something very close to what is being explained. I do have a bad o2 (the rear one) the wires were ripped off and it is not hooked up (previous owner?) I just bought this thing.