I'm new to the jeep world. My buddy was deploying to iraq and gave me his 1998 XJ 4.0 as a wedding present.

The only issue I'm having with the thing is that after a cold start it will start fine, but then after about a minute into driving the engine will hesitate for about 5 seconds and then I will hear a backfire from under the hood and all power returns. This happens about twice before the thing has warmed up. When the engine is warm everything is fine. I have checked the basics and everything seems fine. I'm open to any suggestions.

James


*** PRE CAT O2 SENSOR FIXED PROBLEM ***

 

Perhaps you should go to the repair factory. I think that it's ok. I'm sorry for this problem. I didn't meet the seem problem

 

FIXED : Put in a new pre cat. O2 sensor and it fixed the problem. The strange thing is I had no faults for the 02 Senor or heater circut. The problem I was having was when the DME would switch from open to closed loop. The DME thought the O2 sensor was up to operating temp, but it really was not. I bet this caused the car to go very lean for about 15 seconds.

The simple fact is this fixed the Hesitation problem. I have read many posts and everyone is clueless, but you veteran posters do know about Tires/Lifts. The thing is they dont help you out if your car doesn't run.

 

Hi, check fuel pressure and IAC. I had this problem (more or less). My fuel pump was very "tired". I changed it, and fixed my problem. Have a good day