Head Scratcher

[yellowjeep101]

Thanks, I'm going to see him after work, I love the motor, just the jeep around it is being a B-*** to deal with

[yellowjeep101]

Alright, still not fixed, tried resetting the timing, so I guess that could be crossed off the list of things it may be. But timing is on the right track. Any ideas?

[jkrubi]

Did you check for vacuum leaks with quick start/propane or water? What way is the backfire going( intake or exhaust)? So a couple more ideas for you...... Did you change the plugs and wires ( gapped, no bad wires), cap and rotor? Could you have installed a bad one ( even if it's new). Find a set off a good runnin eng and try them. I've had bad plugs before ( new) and wires go bad ( old). Anything plugging the intake making it run rich? (dirty filter)
Not sure because it's stroked, do you have to run a different timing, or deg on the cam? Is that done correct?

[AV.NINE]

Without a doubt it's the ecu.

Obviously who ever did up the engine would have reprogrammed the ecu to account for a longer stroke of the piston. The ecu is telling the plugs to fire prematurely accounting for the back fire. The longer stroke it takes the more the timing is off from factory. Because our engines don't have distributers, reprogramming the ecu is the ont way to change timing.

Without Brian's ecu you'll have to get yours programmed. Or just go get it from Chanda when they open tomorrow because the longer you run it like that the better chance you'll have of pooching that engine.

Unless what I'm saying has been said already... But change that ecu.

[yellowjeep101]

Checked vacuum and all of the other things on that list, with brake clean and propane, checked timing, replaced tps sensor, spark gaps checked, I'm running low on ideas.

[frenchy]

I could be mistaken, but I swear that engine had a distributor installed last time I saw it.

[yellowjeep101]

Fixed, 02 sensors

[BUKI]

I can honestly say, I didn't see that one. Well good to know anyway

[jandh]

Fixed, 02 sensors

No F'n way, really??

[Dingleberry]

Doesn't surprise me one bit. I've seen so many weird symptoms in my (and other people's) Jeeps that are finally resolved once the o2 sensors are replaced.
Thankfully you got it sorted

[THE GOLD DIIGGER]

Maybe a thanks is in order to the guy that fixed it for you I told you it wasn't a ECM.