TJ running rough, backfiring, spitting raw fuel out of exhaust

[Maddie]

Hi Guys, I am at my wits end with Grumble. After a drive with some friends at night a few weeks ago, I drove into a ditch, almost a deep hole but my momentum pushed me out of it. The jeep hit the hole front right side. Anyhow, after we drove out, it started driving rough at times. And the next day, it started back firing some times. It would drive smooth, then backfire and idle rough and then it started spraying raw fuel out of the exhaust. I could see it like smoke, when I placed my hand to it, my palm would be wet with petrol mist. I cleaned the air filter, the IAC, the Throttle body, reset the ECU (unplugged the battery wires, touched both together, left it for a couple of hours unplugged). It ran very smoothly for the last two weeks but since yesterday, it has started again. Not like before but slight misfires, starting rough at low RPM and running rough at slow speed. When I say petrol msit, I mean real petrol spray. Tried the ECU trick again, but no use for more than half an hour. Has anyone faced this before? I have checked all connections, everything is connected. Also, there are no oxygen sensors in the exhaust. Its a 2000 Wrangler 4.0 l6 Sport.

[Abu Jimmy]

I think you need to do a computer ( diagnostic ) check while its running rough and misfiring . most likely this issue is related to sensors .

[caprihorse]

If there is petrol in exhaust, one cylinder is not running or is running from time to time. This may be caused by broken cable or cable that has shortcut and is sometimes connecting to spark plug or sometimes not or some cable is not sitting properly inside, where it should. I'm not sure if you have central distributor, then check all 6 cables. How? Remove cable from spark plug (at running engine) and hear the engine. If you hear the noise, like not all cylinders running (only 4 are running), the cable is OK and take the next spark plug cable and repeat. Eventually try to bend all cables by hand, to see, which one is the culprit, when misfiring will be obvious.
If you have individual coils, sitting on spark plugs, maybe one of them is 'half broken'. Repeat the same procedure as above.
If this does not help make computer diagnostics. However those small handheld cheap gadgets will not show anything. You would need to see the real computer screen graphs, displaying cylinder work.

[Maddie]

If there is petrol in exhaust, one cylinder is not running or is running from time to time. This may be caused by broken cable or cable that has shortcut and is sometimes connecting to spark plug or sometimes not or some cable is not sitting properly inside, where it should. I'm not sure if you have central distributor, then check all 6 cables. How? Remove cable from spark plug (at running engine) and hear the engine. If you hear the noise, like not all cylinders running (only 4 are running), the cable is OK and take the next spark plug cable and repeat. Eventually try to bend all cables by hand, to see, which one is the culprit, when misfiring will be obvious.
If you have individual coils, sitting on spark plugs, maybe one of them is 'half broken'. Repeat the same procedure as above.
If this does not help make computer diagnostics. However those small handheld cheap gadgets will not show anything. You would need to see the real computer screen graphs, displaying cylinder work.

Thank you very much Chief, it happens on and off but when it does, theres a lot of petrol coming out. There is one single whole Coil pack on the 2000+ Wranglers. I will try to check by Computer first. Maybe its the sensors.

Chief, does something similiar happen with stuck valve lifters?

[Maddie]

I think you need to do a computer ( diagnostic ) check while its running rough and misfiring . most likely this issue is related to sensors .

Abu Jimmy, you have an idea about Stage Two Mopar Cam?

[Abu Jimmy]

Abu Jimmy, you have an idea about Stage Two Mopar Cam?

Am not into engine modifications but stage 2 cam on a stock engine ( not stroked , not boosted ) will result in a rough and unstable idle + engine short life + not noticeable power gain .

If you have 5 k to invest in the engine I would recommend different scenario .