2000 Cherokee Sport
240K miles
everything stock except 3" lift
4.0L
started stuttering on acceleration intermittently and also when it was driven about 40 miles, then it would get worse. Temps are very stable at 190, no other vibrations or issues
I had just installed all new 4 hole injectors because I was getting stuttering on acceleration and i wanted to just rule that part out. The stock injectors were showing cracks and I already had to change two of them due to age.
So I start the thing afterwards and it is running better than ever. I drive it around for 20 minutes and then part it. come out later and start it. get on the highway and it running really nicely, feels like it wants to go fast. very smooth power.
Then I hit a big pothole at 60 and it starts badly stuttering. I was forced to get off the road because of an accident ahead ( thank god ) . headed home because the stuttering was getting worse and power was declining rapidly. Almost made it home but smelled smoke from below. I shut it off and there was literally a fire going on at the muffler( original muffler and cat ) . The fire went out by itself. The end of the cat near the muffler was red hot.
Somehow I am thinking that the muffler or cat is the problem and this has nothing to do with the injectors.
A mechanic recently changed the o2 sensor that is located under the rear of the intake manifold and I check all of the wiring and plugs before taking it out and also after it started stuttering,.
I am going to tow it home tomorrow and cut the muffler off. I was thinking that it was the MAP sensor originally as well as the injectors, however this is a new one for me.
Need some ideas on what to look at
240K miles
everything stock except 3" lift
4.0L
started stuttering on acceleration intermittently and also when it was driven about 40 miles, then it would get worse. Temps are very stable at 190, no other vibrations or issues
I had just installed all new 4 hole injectors because I was getting stuttering on acceleration and i wanted to just rule that part out. The stock injectors were showing cracks and I already had to change two of them due to age.
So I start the thing afterwards and it is running better than ever. I drive it around for 20 minutes and then part it. come out later and start it. get on the highway and it running really nicely, feels like it wants to go fast. very smooth power.
Then I hit a big pothole at 60 and it starts badly stuttering. I was forced to get off the road because of an accident ahead ( thank god ) . headed home because the stuttering was getting worse and power was declining rapidly. Almost made it home but smelled smoke from below. I shut it off and there was literally a fire going on at the muffler( original muffler and cat ) . The fire went out by itself. The end of the cat near the muffler was red hot.
Somehow I am thinking that the muffler or cat is the problem and this has nothing to do with the injectors.
A mechanic recently changed the o2 sensor that is located under the rear of the intake manifold and I check all of the wiring and plugs before taking it out and also after it started stuttering,.
I am going to tow it home tomorrow and cut the muffler off. I was thinking that it was the MAP sensor originally as well as the injectors, however this is a new one for me.
Need some ideas on what to look at
