One normal plug, 5 fouled

[rmiller]

I just bought an '02 Liberty that misfires very bad and runs obviously rich. The fuel coming out of the exhaust practically condenses in my nostrils, and it's basically not drivable. I pulled the plugs out and I have 5 covered in carbon, and one (cyl #5 - rearmost driver side) normal.

I figured a compression check would be a good thing to do at this point, so I threaded in my gauge, pulled the fuse for the injectors, and turned the ignition but the starer just spins, the solenoid is apparently not engaging the flywheel. What is the correct way to check compression on this car?

Any ideas/pointers? I appreciate the help!!

 

[rmiller]

No ideas? I should mention that there is a high pitched pinging from the engine when I load the engine with say 1/2 throttle. Also still not sure how to check the compression...searched the forum no luck.

Thanks again! Want to get this sucker running right asap.

 

[LibertyTC]

How many miles on this KJ?
Super rich, pinging, the first thing that comes to mind is timing and or chain & lifters.
What Check engine codes are you able to pull?

 

[rmiller]

130,000 miles. There is no CEL, and I have yet to plug in a scanner. I'll have to do that tomorrow. I'm surprised though there isn't a light based on how bad it's running. The 5 fouled plugs smelled of gas when pulled as well.

 

[LibertyTC]

Did this condition just all of a sudden leave you where it is now, or was it rough running for quite some time?

 

[rmiller]

Started all of a sudden.

 

[LibertyTC]

It was fine... and then when you started in the am cold it was like this?
Do you have any manuals/FSM?

 

[rmiller]

Well I bought the car today in it's current condition. Previous owner said it ran normally in the morning, then began running rough on the way home from work. Not sure if that was after a cold start or suddenly while running. Buying a Bentley or other preferred manual is on my list of things...

 

[LibertyTC]

Just so ya know we do not call Jeeps ....cars in here. (offensive language not needed) LOL.
Ok so you bought a Jeep as is..I find it also hard to believe there are no codes either.
So lets get ya to scan the codes if there are any. You can try the key trick without starting the jeep..turn key ON-OFF-ON-OFF-ON ....and leave it in the ON position.
Any codes will be shown in the odometer or it will say done if you got the sequence right.

 

[rmiller]

Excellent, I'll give that a shot on my new...rig (?). Also, any ideas on the compression checking?

 

[LibertyTC]

Are you able to connect the compression gauge and turn engine over?
02-'04 3.7 has 9.1:1 compression ratio,cylinder pressure should be between 170psi-225psi with no more then 25% difference.
This should help ...
40743[/ATTACH]"]

You must be registered for see images attach

 

[rmiller]

Ok, I got a obd2 scanner and threw code p0725 (engine speed sensor circuit). Upon searching I found out a crank position sensor malfunction is a common cause of throwing that code, so I replaced it. Started it up and read the codes and the 0725 is gone, but I now have codes p0155 and p0161 (bank 2 O2 sensors). Compression check is next up.

Thanks again,
Ryan

 

[rmiller]

Ok, compression numbers (these are dry & cold values) I think give away the problem:

1: 165
2: 175
3: 175
4: 181
5: 170
6: 0

So I must have a valve stuck open, right?

 

[rmiller]

Oh and for the record I discovered an effective way to remove the crank position sensor during my little diagnostic escapade. That thing was really stuck in there, even after soaking in pb blaster. I searched about this and found people suggesting breaking it off and drilling it out.

Instead, I grabbed my tie rod separator, tapped it into the sensor so that the forks sandwiched it, and with a little leverage wacked the handle with my palm. This backed the thing right up. However, disclaimer: may destroy sensor in the process. Mine was a little beat up after that.

 

[Neal]

Yes, valve stuck open, but the piston must be hitting the valve too! Pull the valve cover and see if rocker is off.

 

[rmiller]

Hoping to get to that tomorrow. What would cause the rocker to jump off?

 

[Neal]

I think they are on pressed in studs, but thinking more that would keep the valve closed---
There has been issues with valve springs breaking--that sounds more like it.

 

[rmiller]

Yeah I read about the valvespring issue. Will post what I find when I open up the valve cover, hopefully tomorrow.

 

[rmiller]

Well, I think I found the issue. Broken exhaust valvespring cyl#6.

You must be registered for see images

 

[LibertyTC]

I thought 6 had no compression....
What's next pull the head & Rebuild it? (I would)
Wonder what pistons look like?