I've never been so happy to find something wrong.

[Jtrux]

I purchased my MJ a few months back and have been chasing little issues regularly since.

 

One big one was that it idled rough and exhibited very poor vacuum. I went round and round trying everything that made sense but nothing fixed it.

 

The engine has 64k original miles so by default I ruled out any internal issues right off the bat because I didn't think it was likely.

 

Well, I finally decided to buy a compression checker and see if anything was going on.

 

#1 115 psi

 

#2 120 psi

 

#3 0 psi

 

#4 125 psi

 

Hmmmm...

 

Pulled the valve cover off to discover that the intake valve in that cylinder was stuck open and a push rid had been bent.

 

The truck sat for every bit of 10 years undisturbed prior to me acquiring it so I suppose that contributed to the issue.

 

I have not determined if the valve is bent or not yet. I will remove the spring tomorrow and attempt to free the stuck valve. Don't worry, I will bring that piston to TDC as to not risk dropping it in the cylinder.

 

I'm hoping it is a simple fix and I can finally get the old girl back on the road.

 

Unfortunately, I had become fixated on vacuum leaks and refused to think that anything else could possibly be an issue.

 

My name is Josh. Josh is dumb. Don't be like Josh.

[91Pioneer]

Another trick is to insert nylon rope through the spark plug hole after moving the piston up. That helps take up more space so the valve can't drop. Be sure to leave some rope sticking out so you can pull it out when you're done.

[banshee]

Another trick is to insert nylon rope through the spark plug hole after moving the piston up. That helps take up more space so the valve can't drop. Be sure to leave some rope sticking out so you can pull it out when you're done.

Great trick used it many times, used to use an air line to pressurize cylinder until an older mechanic told me this about the rope

 

Sent from my LG-D631 using Tapatalk

[86FUBAR]

Why not try and use the rope method to help push the stuck valve closed ? If it's not bent and done carefully it should work , also if possible try and squirt some oil on the valve through the spark plug hole .

[Jtrux]

I got it fixed without having to remove the valve spring.

[86FUBAR]

I got it fixed without having to remove the valve spring.

This is were you telling us how you fixed it ! ........ helps us and anyone reading this post possibly resolve the same or a similar issue later on and keeps this post from turning into another statistic. I.E. Another 1 of a 1000 posts stating an issue but no fix for said issue .