For some time I have experienced a chugging problem with my Jeep. The mechanic suggested that it could be the ignition coil, which could have an issue when the outside temperature heats up. I live in AZ. The coil has been replaced twice, the second time the fix lasted not even a week. The vehicle has been mine, and lived in AZ since I purchased it in 1992. As the Jeep aged, Occasionally, there would be chugging which could be cured by shifting into neutral and gunning the engine, and returning to drive. Recently, After a very expensive effort to return the AC to working condition, my mechanic attempeted to solve the problem with the chugging. If I described the problem as bucking, stuttering as the vehicle is driving down the road it would be exact. Now, I the vehicle is sitting in the drive way waiting for me to decide what to do next. It has 227,000 miles, 4x4, straight 6, and has been well cared for all of it’s life. Xfer case is in perfect condition. The trans was just serviced, it has a new fuel pump. I have enjoyed the vehicle, and would prefer not to get rid of it, but I feel it is dangerous to drive in this condition. Any suggestions??
With that many miles on the engine, you might want to have someone check to see if the timing chain is stretched.