I got a ls swap in a ef when i first got it running it ran fine then 2 days later i find out my timing belt was loose. I drove it lastnight and it was backfiring alot out of the exhaust and was running really slugish. I had put it in my garage this morning but didnt have time to look at it. When i started it it was misfiring bad you can hear it because i have it open header it didnt sound they way it used to when i first got it started. and it seemed like it had a mean power loss. Could it have jumped a tooth or two? Or something else wrong with it? If any1 can give me some answers that would help alot.

 

Yep, it could have jumped time. Check that first since you already figured out the timing belt was loose.

 

^^^^ Totally agree. Since the belt is loose just replace it, it dont cost that much.

 

checked it out today and it jumped a tooth. gnna get a timing belt tmrw and put it on time it n see what it does. if i have a bent valve i guess its time for a build.