Last year the 1999 Jeep did the same thing. Took it to the mechanic and they said it was the throttle control value. They also replace the spark plug wire and plugs with a turn up along with the throttle control value.. The Jeep ran good for a year, then started doing it again. When you start the Jeep up it runs good for about 30 seconds then it run real rough. Clears up for a few minutes, then when its totally warm, it runs rough again. Took it back into the shop and they said nothing showing on computer read out. They said they dont know whats wrong maybe its the (Brain Box) but they are not sure. Told us to take it to a Jeep dealer. Any suggestions or help would be very appreciate before I go anywhere else and lose money :uhoh:
Thank You Gary and Gayle Siler