Workingwizard

I have a 98 Cherokee Sport 6cyl.

I need advice from someone that has actualy fixed a sputtering problem that occurs at acceleration.


Problem:
While driving either through neighborhood or freeway, engine stalls, sputters, hesitats only when accelerating. using cruise control on freeway runs just fine.

Comments:
Starts just fine, both cold and warm.
Idles fine in Park.
Revs up just fine in park.
No Check Engine Codes.
No Engine Knocks
Cleaned Throttle Body

Replaced:
Header
Muffler
O2 upstream(Bosch)
MAP sensor
SparkPlugs
Rotar and Cap
Plug Wires

Checked:
Electrial Connector Plugs
Looked for Damaged Wires
Fuel Pressure at Rail is 45psi

Does anyone have suggestions on what maybe the problem? and Why?
I have found many posts that mirror my problem, but no one realy follows up with what ended up fixing the problem.


Thanks to anyone providing support.

XJ Stryker

Yes my Jeep used to sputter and nothing else. Took me awhile to find it but it was the CPS on mine. I fixed it with the simple unplug and replug in later ofcourse my CPS started doing other Funky things (CPS is the weirdest electrical component on your truck and can cause MANY different faults almost never the same).

I have since replaced it finally and truck runs great.

CodeXJ

Are the plugs gapped correctly?

Workingwizard

XJ Styker, I will try that.
CodeXJ, Plugs are Gapped at 0.035, I just replaced and Gapped them a few days ago.

Andrew0257

Did it sputter before you replaced the plugs?

joelfett

Check your TPS (Throttle Position Sensor) behind the throttle body. Mine had the same syptoms you have when I bought the XJ and went through 2 of these, each time I washed the engine compartment. I ended up putting an O-ring on the damn thing to help with the moisture issue. Haven't had a problem since (3 years at least now on the same TPS. I hope this helps.

Workingwizard

Andrew, It has been sputtering for awhile now. seems to be slowly getting worse. So, Yes, It was sputtering before i replaced, Plugs, Wires, Rotor & Cap, MAP sensor.

Joel, will the TPS cause the sputtering on accelleration only? I will note that this seems to happen when driving only, sitting in the driveway reving the engine has no sputtering at all.

Thanks for everyone's help!!

1truckdriver

I just changed my CPS (crankshaft position sensor) not camshaft. It connects at the back and on top of the engine, and goes down between the eng and the firewall to the top of the transmission bell housing. Very tough to get to, and very hard to see. The wires were frayed at the connection on the bell housing (couldnt tell until i took it off) the new one cost 32.00. It started as hesitation when I accelerated and on bumps in the road, then it was not fireing when I tried to start on moist mornings, so I did the unplug and plug the sensors thing and It seamed to work until it got more frequent. I found out thet when I unpluged the sensor I wasmoving the whole wire (its short) and causing it to make contact. Long story short, I replaced it and I have no hesitation and starts like a charm.
P.S. 240,000 miles!!!

Workingwizard

Update:

I replaced the crankshaft position sensor today with a new one. There is no change in performance.

In the morning or when the engine is cold, jeep starts and runs great!! Acceleration on freeway is good, no hesitation or bucking. Only after about 10min if driving does things start going bad. Seems like some component gets hot and starts to fail. Thus causing jeep to hesitate and buck.

Running out of sensors to replace and things to check.

Still looking for suggestions.

Andrew0257

How old is the ignition coil? When the get old they will break down under heat and/or load. On my old yj it got so bad it would shut off and I would have to pop the hood so it could cool down then would restart. Replaced it ran great.

truckntractorhick

yea x2 ^^

Workingwizard

I only purchased the jeep (aka, money pit) a few months ago. It has 185,000 miles.
Coil looks like original equipment.

Andrew0257

Change it they are about $30 and if it doesn't work atleast you will know that its good.

Andrew0257

10min uninstall/install

Workingwizard

Yea, I will do that this weekend.
I will post results.
Thanks guys!!