OK…I have a '99 Cherokee sport which I got a year ago. I love it, but it developed a mysterious engine problem a few months after purchase. Whenever I start up the engine - whether it's been resting for days or just ten minutes - it drives fine for a few minutes and then struggles to idle, starts to stall, and the RPM's surge as if it's struggling to maintain power. As the engine struggles, there are small backfires from under the hood. I pull over, stop the engine and restart it, which pretty much always solves the problem for the rest of the trip. I have tried a lot of different approaches, and know that it's not; faulty O2 sensors, the crank position sensor, the vacuum or either OBD unit. It shifts smoothly and does not seem to be the transmission. Most recently I was told it could just be a faulty ECM, and that a new one could be the solution…any similar experiences or advice is welcome! Thanks...