Misfire

The BAD Influence

The BAD Influence

Active Member
I have a 98 XJ with the 4.0. Running rough. Throwing misfire codes. I've changed the coil, distributor cap, rotor, plugs, wires and O2 sensor. If anything it's running worse. The only thing I can think of is the timing chain since it has 224,000 miles. Anyone have any ideas before I tackle the big job of changing the chain?
 
krdadlamb said:
I have a 98 XJ with the 4.0. Running rough. Throwing misfire codes. I've changed the coil, distributor cap, rotor, plugs, wires and O2 sensor. If anything it's running worse. The only thing I can think of is the timing chain since it has 224,000 miles. Anyone have any ideas before I tackle the big job of changing the chain?
Click to expand...

It’s been awhile since I’ve been around one, but they ran a vacuum system, correct? Have you checked for any vacuum leaks? That could definitely be a factor if it does.


Sent from my iPhone using WAYALIFE mobile app
 
wjtstudios said:
It’s been awhile since I’ve been around one, but they ran a vacuum system, correct? Have you checked for any vacuum leaks? That could definitely be a factor if it does.


Sent from my iPhone using WAYALIFE mobile app
Click to expand...

I haven't checked anything to do with the vacuum. My reason for leaning towards the chain is the rotor post is clearly only firing on one end, not getting a good contact all the way across. I know the chains are known for stretching, so....
 
krdadlamb said:
I haven't checked anything to do with the vacuum. My reason for leaning towards the chain is the rotor post is clearly only firing on one end, not getting a good contact all the way across. I know the chains are known for stretching, so....
Click to expand...

Yeah, good point. I was thinking vacuum advance on the timing. But that wouldn’t explain the rotor post.


Sent from my iPhone using WAYALIFE mobile app
 
wjtstudios said:
Yeah, good point. I was thinking vacuum advance on the timing. But that wouldn’t explain the rotor post.


Sent from my iPhone using WAYALIFE mobile app
Click to expand...

As I stated, I replaced the rotor and cap, but not the entire distributor nor the cam position sensor. Would either of those make any difference or should I just accept the fact I've got to tear into it and replace the chain?
 
krdadlamb said:
As I stated, I replaced the rotor and cap, but not the entire distributor nor the cam position sensor. Would either of those make any difference or should I just accept the fact I've got to tear into it and replace the chain?
Click to expand...

I hate to have you throw parts at it, but all three I would guess would cause the misfire. I don't know enough about that engine to say for sure, it would be a hell of a lot easier to try a new distributor and or a cam sensor first before you tear it down. Nothing worst tearing the engine down to do the chain to find out it was one the other two!! I wish I could be of more help, good luck.
 
Update

I went ahead and did the timing chain, it was definitely stretched. But didn't fix the problem. So I checked the compression. Started on cylinder 1, it only had 50, 2 had 120, 3 didn't even register, so I quit. I'm hoping it's just valves and not a piston.
 
krdadlamb said:
I went ahead and did the timing chain, it was definitely stretched. But didn't fix the problem. So I checked the compression. Started on cylinder 1, it only had 50, 2 had 120, 3 didn't even register, so I quit. I'm hoping it's just valves and not a piston.
Click to expand...

Yeah, that’s not going in the right direction. Good luck


Sent from my iPhone using WAYALIFE mobile app
 
You must log in or register to reply here.
Top Bottom