LLY: low compression, hard starting and misfiring

[dirtymax36]

On my lly i just did a head stud and gasket job, and after this i didnt re do valve lash unfortunately when i put billet pushrods in and ran it for just a few days, my retarded mistake. now it cranks over twice before starting hard and it is only producing around 245 psi of compression on each cylinder. i have one injector +6 and another +4. what could my problem be besides a belt valve? local shop says its my valves or rings and the heads need to be pulled. Any help is appreciated i just need to get this problem sorted out before i have the heads pulled and spend more money than necissary. Thanks!

 

[Evan@InglewoodTrans]

What do you mean by you didn't redo valve lash? Did you just take the rocker shaft off without loosening the adjusters and then just put it back on?

 

[Chevy1925]

leak down test, or pull the valve covers and check lash to see if you bent things or are just holding valves open from not adjusting lash

 

[dirtymax36]

The shop pulled the glow plugs for the test. Should I have them check lash again before they pull the head

 

[Crawler]

The shop pulled the glow plugs for the test. Should I have them check lash again before they pull the head

Yes

 

[DIESELMAFIAPER.LB7]

What do you mean by you didn't redo valve lash? Did you just take the rocker shaft off without loosening the adjusters and then just put it back on?

You mean that's bad

 

[Kappa9012]

if you didn't reset lash, there's a good chance you bent a valve... recheck compression, find your low cyinder/cylinders, pull the valve covers and start looking at valve stem projection... if you keep running the engine and a valve is actually bent it will eventually drop and you'll be looking for a new motor.

 

[Evan@InglewoodTrans]

You mean that's bad

Depends on what the desired end result is It's been done with success before but it's nothing I would ever try.

 

[Kappa9012]

what did you ever find?

 

[dirtymax36]

sorry i havent replied on here recently, it ended up being bent valves

 

[Kappa9012]

sorry to hear that.

 

[dirtymax36]

Shit happens and I learn from mistakes. Except this was a very expensive one

 

[Utahski]

sorry i havent replied on here recently, it ended up being bent valves

Stock pushrods are plenty strong. You don't need "billet pushrods" or whatever kind of super thing you put in there. When there's a problem it's the weakest link that goes. Better to have something bend than break. And a bent pushrod is lots easier to fix than a bent valve. You screwed up to begin with and it got you worse because of those pushrods.