96 XJ Running Rough..thowing mulitple codes

[Bobby@Bullydog]

Ok so Ive searched everywhere and done everything known to man BUT solve my problem with this.

Basically I bought it Jeep and it was running rough...would blow some black smoke when heavy in the throttle.

Threw a p0171 - System Too Lean
Replaced the first o2 sensor and that code went away

Then a week later the light comes back on and it starts running rough again..no smoke now but it trys to idle very low around 400-500 rpm and sputters at idle like a tractor. runs fine off idle and through the rest of the RPM range though.

I get these codes now

p0300
p0301
p0303


I was able to swap injectors this weekend. Just swapped one and two beings it was throwing a code for misfire on 1 and 3. Didnt change a thing so it still comes up Misfire on 1 and 3. So that rules out the injectors, plugs, wires, cap, rotor, pick up coil. Not sure what else to check other than swap out with another ECM.

Got another code on start up this morning P0141 Oxy Sens Heater Circ (bank1, Sens2)


Any ideas guys?

[lawsoncl]

Is the O2 sensor wiring still intact and not up against the header?

[Bobby@Bullydog]

Yea all the wiring is good there. Ive pretty ran over everything I could think of and now im just stumped and had to resort to getting help. Hurts my pride not being able to fix it myself.

[lawsoncl]

I believe there is a fuse for the O2 sensor heater in the PDC? Sens 2 would be the downstream sensor I think. I missed how you eliminated plugs, wires, cap and rotor? Throttle body and idle air controller nice and clean?

[Bobby@Bullydog]

Eliminated them by replacing it all!!

IAC is clean and working properly and so is the TB.
I actually ran some Sea Foam through that and cleaned all the carbon out of the motor.

[Bobby@Bullydog]

Any other ideas?

[Bobby@Bullydog]

Still running rough guys....got a whopping 13mpg on the last tank!!!

This is driving me nuts

[jneary]

compression test

[89xj]

Originally Posted by Bobby@Bullydog

Got another code on start up this morning P0141 Oxy Sens Heater Circ (bank1, Sens2)


Any ideas guys?

isnt there a fuse for the o2 heater curcuit?

[Bobby@Bullydog]

Originally Posted by 89xj

isnt there a fuse for the o2 heater curcuit?

I dont have a clue. If i do i cant tell which fuse it would be because the cover is gone.
Anyone have a diagram of the fuse panel layout?

[Wayne Sihler]

Originally Posted by 89xj

isnt there a fuse for the o2 heater curcuit?

yes It is powered thru the ASD relay.Fuse # 20 -30A
If that fuse was blown -you wouldn,t be having a miss-fire-- It would be a No Start condition.

Have you replaced the distributor ? A worn shaft/bushings will cause a miss fire.Keep it up long enough and the cat will be gone too.

Wayne

[Bobby@Bullydog]

No i didnt replace the Distributor...wouldnt make sense to only misfire on 1 and 3 though.

and the cat has already been removed...dummy pipe in place with an o2 sensor in it.

[winterbeater]

Not a bad idea to pull the disributor cap and wiggle the rotor/shaft for free play. Forget about replacing......check.

[Bobby@Bullydog]

dizzy is in there snug...gear isnt worn at all

next lol

[winterbeater]

What about the compression test? Don't guess any more whether the valves and rings are sealing good enough.