Head replacement

[Junkyjeep]

2002 Liberty 3.7 157,000 miles
I just replaced the right side head with a rebuilt head. Trying to start it and it seems out of time but after cranking for a bit it fires up and runs great for about a minute or so then starts misfiring and dies. Now it won’t start up again. Any ideas? Thanks

 

[phissure]

Are you getting any codes?

 

[Robochop]

2002 Liberty 3.7 157,000 miles
I just replaced the right side head with a rebuilt head. Trying to start it and it seems out of time but after cranking for a bit it fires up and runs great for about a minute or so then starts misfiring and dies. Now it won’t start up again. Any ideas? Thanks

Did you reset the timing or put it back in the exact same spot?