4.0L crapping out on me.

OK. So last week I changed the plugs and wires on my 97'. Turned on the first time and ran fine. Would not ignite the second time starting so I changed the plugs again. Started it up and drove it to a mechanic incase it died again. Get to the mechanic, try to start it again and nothing. Engine wont even turn over. Mechanic wiggles battery terminals and Jeep starts. Jeep ran, but not well. The Jeep would miss every once in a while. Got home and changed the plug wires again and cleaned the battery terminals. Now the Jeep will start, but wont idle. The RPM's are all over the place and it's missing like a bad batter. I barely get it to the mechanic. It stalled twice on the way over and I had to keep the engine above 1500 RPMs to keep it from dying when it missed. So... my question is what is God's name would cause my engine to miss and barely run by just changing the plugs(twice), wires(twice), and cleaning the battery terminal. I finally got a Check Engine light on the way to the mechanic. I don't know what code it is saying, but I'm just trying to get a rough estimate of what went wrong. Please Help!

What kind of plugs and whose brand of wires, also did you do the cap and rotor ?? Is the cap seated right and are the wires seated on both the cap and the plugs and finally are you sure you did not mix up the wires and cylinders

Could be a lotta things, but going with your clues -

It ran fine before and this was just usual maint. (?) - so probably something you did did this.

It runs fine first crank, but not second. Is the first cold and the next after it's warmed up? Probably the difference between open and closed loop.

Bad battery connection - did you touch these, perhaps disco them while doing the plugs? Probably not the current problem if cleaned well and it starts fine.

Check engine light will probably say something about a sensor or not being able to bring something into line.

Seeing as how you were under the hood, and the nature of the sudden impact, it sounds like you may have knocked a vacuum hose loose or cracked a plastic one, or took a connector to a sensor off that is ignored while cold and not replaced it properly.

Try going through ALL the things you did the first time around and see if you think of anything you did to get at the plugs besides just turn them out. Report back if you think of anything else that might have happened.

Check everything the other posters said to check also the source of your problem may be because you disconnected the battery and the computer hasn't reset itself this happened to me about 2 months ago when I killed my battery . I replaced it and then my xj ran like crap (sort of what your discribing) . I just started it up and drove it down the road and beat the crap out of it for about 5 minutes and it magically started running great again.Im not saying that this is what fixed it but i know it has worked for me a bunch of times with different vehicles.

The Plugs are Autolite plugs (cant remember model number but they have one prong? on the end). The wires are Bosch. I never disconnected the battery until the day it really started to mess up. After I disconnected the battery all these problems started to happen. I too thought that the computer may have reset itself, but I ran the Jeep for as long as I could stand. The engine was really straining and making awful sounds so I just couldn't bring myself to let it run for longer. When I changed the plugs and wires I didn't disconnect the battery and I did each plug and wire one at a time so I wouldnt get them all mixed up. There is obviously something very electrically wrong with my Jeep, because the whole problem started when I disconnected the battery. I decided to change the plug wires after the Jeep was already doing this. I thought it might help (but it didnt). Anyway, I'm leaving for a few days, so I wont be able to post again until sunday night.