changed plugs today on my 01 auto 4.0. it will start but acts like it does not want to. it runs just fine after starting. I think it is either the spark coil rail or some wire I knocked out of whack. any suggestions. It started super fine before the plug change.

 

Bump. This kinda thing happens to me a lot, its the price we pay for wanting to improve something

Until someone else chimes in, I'm gonna say maybe an electrode isnt gapped right, you may have broken old brittle wiring in one of the harnesses, or connection between plug and coil isnt as tight as it should be.

 

What kind of plug did you install?

 

champion 3034. it turned out to be the battery. I looked to see how old the battery was since last week my wife let it go dead. I went to NAPA and got a new one. It fired instantly. Someone on this or another jeep forum stated that jeep's need a good battery or they become hard to start.