Check Engine Light decided to rear its ugly head again....

[alexfm]

Well, Thursday morning, I was driving to work as usual, and out of no where, the Jeep started to feel like it was randomly misfiring, or losing power and then coming back. At first it only did it at anything above 35 mph, below that, or at idle it did not stutter. When I got to work, I popped the hood, and check the spark plugs, making sure the boots were on tight, and they were. SO I went in and worked, and when I left to drive home, it started doing the same thing again. So I get home, and leave it alone, as it frustrated me to no end, and the misfire was really bad on the way home. Fast forward to yesterday, and me and my dad are looking at it, and check the codes (ignition method) and it says the codes are 35 and 22. I also changed to spark plugs and wires as well as ditributor cap, which did nothing to help the problem. But after changing those parts, the misfire became apparent at idle, as well as this wierd static over the radio. We checked codes again, and it said the same thing, codes 35 and 22.

My question to you all is: what the heck do you think the problem could be? Im working on it, but as far as I know, the temp sensor is fine, and we couldnt find anything wrong with the fan circuit.

Any help would be greatly appreciated,

Alex.

[bob91yj]

OBD 1 codes can be found here...

http://xjjeep.com/2007/09/24/obd-codes/

[shortbus4x4]

You have the sparkplug wires routed correctly right? Not wrapped around other parts of the wiring harness. How is your alternator, I have seen bad alternators do funny things to computer controlled vehicles. Check your battery terminals too.

[jmxj]

well, if it was just misfire at idle after changing plugs and wires, I would say check to make sure you did not put plug wires back in out of order.

but codes
22 Coolant sensor signal out of range – May have been disconnected to set timing
35 idle switch motor fault – check connections

so, 2 different sensors out of range or saying check connections with the static over radio I would say start checking grounds, major ones first to include one on back of block and one at ecu.

[alexfm]

Thansk for the help everyone. Yea, the plug wires were run correctly, and I did replace the battery ground (old one was dying anyways). Just an update, I was considering getting another cherokee to replace this one, with its mysterious problems, and lo and behold, as soon as I go out to look at other cars, it starts working again. No joke, everything dissapeared, no sputtering, no misfire, no CEL, nothing. Thats what happened last time too. Oh well. ON the plus side, it runs much better with the new plugs and such.

alex.

[BIGdaddy]

Thansk for the help everyone. Yea, the plug wires were run correctly, and I did replace the battery ground (old one was dying anyways). Just an update, I was considering getting another cherokee to replace this one, with its mysterious problems, and lo and behold, as soon as I go out to look at other cars, it starts working again. No joke, everything dissapeared, no sputtering, no misfire, no CEL, nothing. Thats what happened last time too. Oh well. ON the plus side, it runs much better with the new plugs and such.

alex.

Well...THAT's pretty strange, dude..lol.

[theksmith]

had it been raining before the problems and then dried out when they stopped? thinking maybe connections getting wet and causing issues.

otherwise you probably still have a loose ground or other common connector somewhere and it's just kinda being good or bad depending on how the bumps in the road that day affected it!

[steevo67]

Sounds like a throttle position sensor (TPS). It is usually intermittent like you describe, and the computer will register a misfire code which makes you chase your tail. If it occurs again, I'd change the TPS.

[alexfm]

Well...THAT's pretty strange, dude..lol.

Yea, it is kinda wierd.

had it been raining before the problems and then dried out when they stopped? thinking maybe connections getting wet and causing issues.

otherwise you probably still have a loose ground or other common connector somewhere and it's just kinda being good or bad depending on how the bumps in the road that day affected it!

Actually, I think it may have been raining before it started.. I dont remember exactly though.

Sounds like a throttle position sensor (TPS). It is usually intermittent like you describe, and the computer will register a misfire code which makes you chase your tail. If it occurs again, I'd change the TPS.

Yea, thats what my Dad had figured it could be. He read up on that, and thought that could be it, and then the problem went away, and we kinda stopped worrying about it.

[Hill, Bill E.]

Actually, I think it may have been raining before it started.. I dont remember exactly though.

Rain, driving through big puddles, pressure washing/auto car wash-all of these can mess up the XJ's ECU/PCM box.

Mine did that, and would throw the TPS code.

Turned out that a PO removed the small rubber plug from the back of the PCM. Whenever it got wet, it went haywire.

Replaced the plug, haven't had a problem yet.