89/cherokee 4.0 running rich

[fishskuller]

89 jeep cherokee L6 4.0l has been sputtering up hill on accelerating and failed inspection for carbon monoxide level.so i put it on a diagnostic tester and all the sensor's were going wacky.it was running from rich to lean. All the wires and plugs are good, so i turned the distributer a hair to try and adjust the timing and evrything started working correctly and it was running lean, all the sensor's were fine, then after a couple of day's it started to sputter a little at high speeds. Could this be a timing chain problem or is there a better way to get the timing set correctly? please help this has been going on for a while oh and the distributer is recently new,it's been replaced a couple of month's ago.

[XJeffect]

Is your o2 sensor good? If so then, go around and check all of you major grounds to make sure they are clean and well connected. Nearly every weird electrical prob is always caused by bad lead connections.

[fishskuller]

O2 was replaced 5yrs ago. it seems like the timing is off, because when i moved the distributor a hair the o2 sensor read fine and the jeep ran lean, TB is a little dirty. Is there any special way to clean it without taking it off? i'll guess i'll check all the wiring again also, Thanks alot for your help.

[sparkyshotrods25]

you need to check the timing and the O2 sensor.first off.It sounds like it is lighting the gas on the exhuast cycle and or a poor spark.The O2 sensor if bad will cause the computer to make the fuel to rich if it were bad,and the timing is off it will cause the comp to compensate it and the combined problems will make a sick jeep.I hate that