Ok guys before all the flaming begines, I have searched, but haven't found the answer, so Iam rebuilding. But for some reason I can't find the how to on timing for the LNF , I did a few weeks ago but for the life if me I can't find it again. I keep getting slack between the cams. Even after the new tens springs out. Can someone point me to the gm specs on this?

 

Follow the lsj build book. Did you even release the tensioner? You have to take something long with a soft tip(no pun intended) and put it on the chain against the guide in the location where the tensioner is. I use a screwdriver wrapped in a rag/towel. Smack it generously with a hammer. Not too hard but not too soft either. Pretty much a heavy tap and it will release.

 

I know how to get the tensioner to work. And I get make the chain tight when all marks are lined up, but when I rotate the crank it will slack between the cams, then go back tight, it's not slipping teeth but it's just sags.

 

Are you rotating the crank the right way? If you go backwards it may have some slack, but if it's pulling the right way the tensioner should absorb all slack. You may get a moment where the exhaust cam jumps forward for a bit as you stop turning the crank and you will see a little bit of slack, but it should be very minor and won't happen in a running engine with constant pull from the crank pulley.

 

Yes, you should rotate the crank clockwise. Also is it a new chain? Over time they stretch if its an older one. But yes, there is no oil pressure therefore the tensioner won't be applying full pressure. Good reason to prime the tensioner. I usually just pull the harness from the coils which is the easiest way and crank the motor over for about 5-10 seconds. I also like to soak my new tensioner in new motor oil before installation but that's just me. You don't have to.

 

There's a fuse labeled "INJ" on the engine fuse box, cuts power to the injectors. Easiest way to spin the motor over without firing and you don't wash any extra fuel down the cylinders like you do if you just pull spark.

 

component soaking - its an old school trick - on our engine builds, both chains, water pump gear assy, both balance shaft gear assy, tensioner and all of the chain guides are soaked together in break-in oil and kept over night in a tub to soak, then pulled out of the tub during the timing chain installation..

as for the timing chains, we recommend to replace them once the head has been removed, using old/stretched chains may cause problems/ headaches down the road.. don't want to take a chance on newly installed components to fail from the start from using old chains.