If you dont mind me asking, what did they cost you?

 

The dealer gives me a 25% discount, so after the discount they were $5.70/ea. Part number 53010388.

 

I have 6 measuring cups for each injector and I check fuel delivery if I suspect injectors. Pretty easy.
I remove fuel rail and install jumper wire in place of fuel relay.

 

well thats not bad, looks like ill have to pick up a set and give it a shot.

 

Might as well put a couple valve seals on too since you will have the springs off.

 

So I think things are only going to get worse. Since this problem has started all I had to do is shut it off and restart it and it would be fine. Now living here in the wonderful state of PA in was 55 degrees the other morning and it took shutting it off 3 or 4 times before it would run good. So I can only imagine how its going to run when it drops down to 0 in a few months

 

I read a tsb today that some newer 4.0's had an issue with exhaust valves not seating proper due to carbon build up. Above, 3,500ish the valves rotate and clean the seats of carbon. Weak springs like Belvedere mentioned will prevent the valves seating and throw a code. Maybe a good Italian tune up will help or just installing stronger springs.

 

Yeah, I have seen that write up, but I'm wondering how long it would take to build the carbon up because I have found out that my jeep has 144k on it but has a jasper engine in it that was put in back in 2005. I purchased it with 107k on it and run it hard and often get it above 3000.... just a thought

 

I was thinking why only cold if it were valvesprings. I guess if they were weak, they couldnt prevent the lifter from pumping up. When you shut it down the lifter might be bleading off. Too thick of oil contributes to pump up which coincides with the prob only cold. You could tape a vac gauge to the windshield and see if the needle swings crazy back and forth when the issue arrises and normalizes when warm. Putting in a super thin multi grade oil (0W-whatever) in and seeing if the problem goes away might be another. If you change those springs, make sure the lifters arent flukey and it wouldnt hurt to check if valve lash is too tight, maybe due to a valve pounded into the seat. Jasper might of decked the block and milled the head which would make for tighter valve lash. Probably, they reused springs so they might have more miles than you know. I don't know the procedure for checking lash on non-adjustable valve train. Maybe an adustable length checking pushrod could be used in comparison to known good cylinder measurements.

 

Ok everyone, answer this............ I have made 3 trips that would normally make the jeep misfire, but I have been running my ac and it has not missed. I even ran it in the morning with 55 degree temps and the CEL flashed twice then stopped and it didnt act up. What would be different?

 

Well everyone I figured out my misfire problem.........I replaced the valve springs and it has been running great ever since, so my guess is that one or both of them where weak and not sealing the valve good and tight.

 

Congrats, and thanks for the update!

 

I suspected the head all along...........via my earlier post on one of your many threads....

Glad you finally got it resolved!

 

Really appreciate the info here! I was having the same issues EXACTLY. Symptoms recently intensified and I was having to coast and restart 5 or 6 times on every driving trip. The result = Broken valve spring on the exhaust valve, cylinder 4.

2001 Cherokee sport, 0331 head, 201k miles

 

valve springs for you too huh?