Thanks Joe for your reply. Yes, the Check Engine light is on. This vehicle ('98) doesn't give flash codes and I don't have a scan tool. Also, I don't believe this model (4.0 L) has an EGR.
I think maybe the key to proper diagnosis of this problem is in taking into account the consistency of the symptoms. The engine always starts, runs, even drives perfectly for about the first minute. Then there is a period of very rough idle, or if driving, acting a bit like it's running out of fuel with sputtering, hesitating, backfiring and jerking forward when I try to compensate by steping on the pedal. This lasts about three minutes, and suddenly the engine runs perfectly again from then on. I can drive all over town without a hint of a problem all day--that is, until I shut off the motor for a few minutes to run into a store or something. Then on restart, the exact cycle repeats itself, one minute of running fine, followed by a few minutes of pretty well non-drivability, and then back to normal. A real puzzler.
Thursday, September 10th, 2009 AT 7:38 AM
