IIRC i read the other day that you have to have a minimum of 90 psi to create an explosion for there to be combustion. If your numbers i correct then i am wrong.

I compression checked mine the other day and here were the results

Cylinders ---PSI

1 --------------95
2 -------------150
3 -------------160
4 -------------160
5 -------------160
6 -------------165

I do have a cylinder 1 misfire though. It has to be a result of the low compression. I am going to have to remove the head soon and see whats going on

 

I was thinking of doing the same, but then I thought 160,000 miles is on this thing, I got 3 kids, and this is my DD. Being 21 my credit is crap and no bank will lend money so I can build my credit (thank you america) so as I pm'd the OP of this thread "time to dust of the ol' bicycle and buy a crate"

 

Well, after all this talk on this thread about the engine running strong and not misfiring, even though I was getting the code, well today it actually misfired. I was on the freeway with my kids and it happened. I immediately took it into my mechanic and he replaced the spark plug for #6 because it was probably fouled. It runs fine now. Wierd. Any thoughts anyone?

 

I always try to fix the root cause so i won't have to do it again. I think something caused your spark plug to foul out. What it was, Not sure bc i am having the same code just in the #1. I have low compression in that cylinder, Still trying to figure out what is causing it

 

I agree, especially since my plugs were changed recently. So what is causing or caused it?

 

did the cat check out ok?

 

Sounds like you have a burned valve in that number one cylinder.

 

Yeah i am pulling the head as soon as i can to fix it, Hopefully thats all that is wrong

 

#6 Misfire again today at over 4K RMP going up a hill. I stopped, shut the engine off, waited about 10 seconds, and started it up again. Check engine light was on, but it was NOT misfiring now after doing that. Wouldn't this mean it is a PCM issue or computer issue? Please chime in oh knowledgeable ones.

 

Check the vendors on this site I think they have them for 85.00 here.Also try fiddleing with the plug ins on the injectors I ve noticed on mine they would loosen up or vibrate loose and I would push them on and my idle would smooth out and yes I would have random miss fires.

 

I keep getting the P0301 cyl1 misfire, not all the time, just when the moon and stars are lined up right. I have been using a full can of Seafoam at every fill up and it has been idling better and better, but still idles like crap. Not the normal smooth car idle I want. I wrapped every fuel injector and the whole rail with heat tape, and that has also helped. Friday another can of seafoam in the gas, I am going to add this stuff until it cleans all the crap out of it. In the fall a new head is going in... Too hot down here right now to do anything...

 

How do these injector wraps look to those that have done it too? I'm still periodically getting the flashing "check engine," light when the RPM's are over 4K. Sometimes the light comes on permanently(#6 misfire), and a week or so ago, I had the misfire. I stopped, shut the engine off, and restarted and it was fine. I'm still wondering if it might be a computer issue. My coil pack is fine. I've changed the oil, seafoamed it twice. O2 Sensors checked out fine. I guess I still need to do a compression check. Does anyone have any idea what could be causing the random misfire, via "check engine," blinking, or an actual misfire? I've noticed the ONLY time it has ever misfired is over 4,300 RPM and over 210. It has never even given me an indication when it is under 210 temp. Should I change out the tstat?

 

I finally took mine to my mechanic, they ran diagnostic after diagnostic on the thing, finally ended up being my injector was toast on 6. I just had the damn things cleaned too, but he said the cleaning must have not helped it any. Maybe you all should look into that.

 

How about if I just buy a fuel injector and replace number 6 and see what happens? It should be pretty easy right? I don't have to bleed the fuel system or anything do I?

 

You may want to ask some of the Jeep Guru's on here. I'd personally say you shouldn't have to bleed the whole system, but I am not positive.