Engine Misfiring - JeepForum.com
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post #1 of 2 Old 05-03-2012, 12:14 PM Thread Starter
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Join Date: May 2012
Location: harlingen
Posts: 1
30 days later, 6 fixes, still misfiring!

Hey guys

K so this is the weirdest problem ever, according to my father and grandfather who have worked on every American engine ever produced.

2000 jeep wrangler 4.0 is misfiring whenever it feels like it, the only things I have found to fix it temporarily are to remove the spark plugs and fuel rail to clean them deeply with carb cleaner. The check engine code reads p0202 cylinder 2 injector is open. so we replaced both injector 2 and 4 because for some odd reason the fix-it page at oreillys says replace injector 4. We played Russian roulette with the injectors and swapped them into random cylinders and waited for the check engine light to come on again, which it did, and it still says p0202.

I also found that when I floor it, it fixes it for time being, then it goes back to missing in lower RPMs, also randomly it fixes itself and when I put it in reverse, it goes back to misfiring as if reverse is the trigger for the whole event.

Also there is white vapor in puffs from the tail pipe looks and smells like almost pure gasoline, and when you first turn it on, there is a lot of water vapor coming from the pipe for almost a good minute or two.

I am down to three things to replace, all of which will be costly either in time, money or both.

Timing chain/sprockets (engine has less than 200k miles but we have already replaced the head because it was preTUPI casting)

The ECU or the main engine wiring harness.

Guys I have been messing with this engine trying different things for close to a month, I need some advice or different point of view on this. All help is appreciated!


PS I have checked every vacuum line and the EGR system.

Last edited by toaster8taco; 05-03-2012 at 12:44 PM. Reason: new title
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post #2 of 2 Old 07-15-2012, 02:06 PM
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2004 WJ 
Join Date: Jan 2011
Location: podunk
Posts: 261
anything? i have the same problem, misses only in reverse and smells like its flooding the engine. got cyl 5 injector circuit open code tho. runs great in all forward gears and revs up smooth in neural and park. idk????

04 WJ stock, saving funds for mods
95 ZJ 30x9.50s kumho at
96 XJ sport with stuff, sold
piraterig is offline  

4.0 , misfire

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