Hello all I'll try to make this short,Jeep was sitting for 3 days then I fired her up, no problems, warmed her up a lil and went to work. It's 12 miles one way.after work same thing, about 60 degrees outside.,going home and hit 4 traffic lights be then got on highway doin about 55-60 mph ,so about 2 miles into that I let off accelerator a lil to stay in speed limit,and Wham!,Jeep stumbled,and no gas peddle feel,like I had no power for 3-4 sec, then she backfired through exhaust ,then cleared out. Made it home and put scanner on,nothin,did live data too, nothin all seems OK.no codes,I've replaced numerous parts over the last year ,alot to list she's been fine although there's still a ghost ,any ideas?? CPS again? ECM ? I'm so stressed over this,I love my ZJ,help please! 216*** miles and runs strong I6 ,thanks for help ,have a good day!

 

You had posted about your ECM being bad.. Did you ever take care of that?

Off the top of my head... I'd start by testing the TPS and MAP sensor. Both are very simple tests with a multimeter.

 

The TPS is new about 600 miles ago,I will do a test on map sensor,never replaced it.pcm?, I'm tryin to see if it's something else and tryin to save the xtra$$ to get one. In the past yr I've replaced the cat,muffler,and pipe. New TPS,IAC,distributor, cap rotor,ignition coil, plugs,shocks ,brakes, rotors,sway bar bushings calipers, and just did a oil change 200 miles ago will be in touch, thanks for your help!

 

Sounds like a momentary loss of ignition. Check for loose connections or plugs, bare wires, etc.

 

That backfire through the exhaust strongly suggest that your ignition quit firing the plugs momentarily for whatever reason dumping unburned fuel into the exhaust system. if you were going fast enough the tranny probably kept the engine turning over enough for it to restart when voltage was restored to the ignition system. Not likely to be the TPS, maybe just a loose or corroded battery cable.

edit to add: looking at your post again you mentioned that the problem occurred when you let off the throttle. Is your battery tied down good? If it is shifting and bouncing around it will cause a lot of problems. also have a look at your motor mounts and transmission mount to make sure the entire power train isn't moving around causing loose connections and bad grounds.

 

LOL Dave, I think we were both typing at the same time. Great minds think alike , I'm just wondering how I fell into that categotry.

 

Cleman and Dave , Thanks for your help,im going to run her tomorrow morning and see how she acts.im off the the weekend and im planning to do excessive research top to bottom again,ill keep you posted,im just paranoid to take the jeep the rest of the week,so ill be drivin wifes blazer, at least the jeeps home and safe hate to spend $$$ on tow truck and added stress to me and the jeep.thanks again!

 

By the way battery is very tight and mounts are in good shape

 

how is the fuel pressure