BlackTNXJ

I have a P0206 code. Related to a cylinder 6 misfire 1997 Cherokee.

I have changed the plugs and wires along with rotor. The cap looked good. Changing these have improved the engine performance but there is still a miss after several minutes of the engine running. I have also cleaned the IAC and the TPS along with the throttle body. All the wiring looks good to the naked eye and no vaccum leaks can be detected.

I am leaning to replacing the #6 injector.

Any ideas or comments?

Radi

Swap it with another and see if the problem moves.

BlackTNXJ

I have a set that was pulled from a 99 XJ, I will probably replace the #6 with one of those and see what happens.

Has anyone had a similar problem or experience??? How was it fixed??

cruiser54

Many people have had this problem but it's not always the same fix. There is no "silver bullet" cure. Follow radi's advice.

NJXJ732

I feel your pain I have a misfire on the 3rd and the 6th I replaced plugs coil packs and fuel injectors finally I checked the compression on the cylinders and they were both low so I'm thinking piston rings maybe sure is a pain in the *** though

cruiser54

My buddy had the same symptoms as you. He used the old water down the throttle body trick and it must have cleaned out some carbon from between the valve and valve seat.

NJXJ732

Thank you il have to give that a try

cruiser54

Do you know the correct way to do it? This is critical.

NJXJ732

I assume by removing it flushing it letting it dry and then putting it back on but I'm not 100%

cruiser54

See post #1 in the attached link. Go easy!!!

http://www.ifish.net/board/showthread.php?t=113798

NJXJ732

Wow thank you il have to give it a try after I read the whole thing I had no idea it could be done like that but it makes sense your basically using steam to do the job

BlackTNXJ

I have a friend that has done the water injection on a Ford 302. He had a miss on rapid acceleration or climbing a tall hill. His 302 was completely rebuilt and him running a higher octane gas solved his problems.

My condition started abruptly with no warning, it drove perfectly the day before and the next time it was cranked is when it showed the irratic idle and the rich exhaust smell.
It has thrown both o2 sensor codes along with the #6 cylinder code. Common sense tells me that a non working or dirty fuel injector would cause the PCM to richen the fuel thus causing the o2 sensor codes. I honestly think that I only have one o2 sensor (the upstream). As I think the cat was removed by a previous owner. I have owned this cherokee for 3 years with no apparent problems. I will replace the #6 injector with a spare that I have and see what happens.

Radi

heh. Coke bottle and water, straight from the old school. (it works)

Isn't there a TSB that addresses this on the later model 4.0's? Something about exhaust valves sticking causing multiple cylinder misfires? Seems they don't rotate when the engine is operated at mostly low RPM.

Edit: Found it:

http://www.wjjeeps.com/tsb/tsb_wj_0900303.pdf

DESERTXJ206

How steady of a stream would you say to use? Would a spray bottle misting into the throttle body do the same trick or do you need a lot more water than that?

Radi

Rev the motor up slightly above idle, trickle water into the throttle body, starting with just a tiny amount, slowly increasing the flow until the engine just begins to slow down or cough and sputter. At that point don't increase the flow any further. 6-8 ounces should be plenty.