02 misfiring

[Jeepdawg97]

Took the 02 out for a drive yesterday and all went well. I stopped at the DG and got a drink for the ride back. When I started up, it had a slight shake to it, but seemed to even out on the ride back. I got in it this morning to go to the store, and it was making all kinds of racket and shaking. I shut it off and came back to it tonight. Same deal, so I put the code reader on, and it came up with Misfires from Cylinder 3 and 4.

Got new plugs and a new ignition rail in the jeep today. Same thing going still. Still 3 and 4 misfiring on the code reader.

WTF going on here. Had been driving great.

Have also noticed that the fuel economy sucked bad right before this happened. Also I am smelling lean fuel after it has been running.

 

[macleanflood]

Need to do a compression test and possibly a leak down test.

I'm getting misfires on all cylinders and my engine is shaking. I'm suspecting cracked piston skirts. I haven't bothered with compression tests.


View: https://youtu.be/zzUSR2w1G9E?si=YnspwEUCUDxVI81g

I picked up a used 97 XJ block and I'm just building a mild stroker. I'll swap motors and then dive into my existing one.

I am throwing a crank position sensor at mine tonight. I did a cap and rotor and noticed excessive play in the distributor shaft (97).

-Mac

 

[Jeepdawg97]

I noticed that the hose going to the pcv valve is cracked. Is that what is causing my issues? Have one on order.

 

[macleanflood]

I noticed that the hose going to the pcv valve is cracked. Is that what is causing my issues? Have one on order.

Maybe.

-Mac

 

[Jeepdawg97]

Need to do a compression test and possibly a leak down test.

I'm getting misfires on all cylinders and my engine is shaking. I'm suspecting cracked piston skirts. I haven't bothered with compression tests.


View: %5BURL%5Dhttps://youtu.be/zzUSR2w1G9E?si=YnspwEUCUDxVI81g[/URL]

I picked up a used 97 XJ block and I'm just building a mild stroker. I'll swap motors and then dive into my existing one.

I am throwing a crank position sensor at mine tonight. I did a cap and rotor and noticed excessive play in the distributor shaft (97).

-Mac

What exactly is a leak down test

 

[macleanflood]

Measures the percentage of air escaping from a cylinder.

Probably completely unnecessary. Sometimes helpful.

If you have no or very little compression you're probably pulling the head...and at that point you can see if you have a valve issue or a hole in a cylinder.

-Mac

 

[Jeepdawg97]

What exactly is a leak down test

Let me know how the crank sensor works out.

 

[macleanflood]

Let me know how the crank sensor works out.

No affect as I figured.

-Mac

 

[Luke90]

is throttle body clean? we got mad looking for my cyl1 misfire and in the end cleaning the throttle body solved the problem more than a month ago. not sure it's the cause of the problem, but may be worth a check.

 

[OilSpot74]

I’ve been lucky that every time I’ve thrown a P0xxx code it’s just been a loose plug wire. I’ve snugged everything down, cleared the codes and all was well. Wish I had better insight for ya.