Okay fellas -

My "new" truck had an awful lot of timing rattle (like it is heavily advanced), so I grabbed a Tech II and checked the timing parameters. The injection timing at idle was 12.5 degrees BTDC. The TDC offset was -.88 degrees. I did a "TDC learn" and the value went to -.33 and the truck quieted down ever so slightly at idle, but was still VERY rattley at RPM.

My question is:

What did you think of this timing at idle? I thought that it seemed high to me.

and

What do you think of this (-.33 deg) TDC offset? How do I get to -1.54 deg?

Do I have to perform an optical bump and a TDC offset learn to get this TDC offset value to change or can it be done strictly by "plugging" in a new value with the Tech II? What menu tree should I follow in the Tech II to plug-in a new value?

I apologize for beating this apparent dead horse:horsey: , but I tried the search function and was left with more questions than answers...:help2:

read over time set in FAQ if that still does not make sense to you shoot us a message back, -.33 is factory setting, if all you did was tTDC learn command it may not gain any advance, may still need to rotate IP a little

Rotate the pump slightly to the drivers side and re-initiate the learn.

Thanks for the reply guys.

I did some more reading and believe that I understand the TDC Learn function better now.

One other question though...What so you make of the 12.5 degrees of timing at idle? I don't have a Service Manual yet (it is on the way), so can you tell me what the pump timing (stock) should be at idle?

Thanks for all of the help for a "new" 6.5. user...:D

P.S. JK - You and I will be talking soon about a new set of injectors...

12.5 timing at idle is somewhat on high side was truck warmed up when you read it may be still on cold advance and what is your idle rpm, once at operating temp 170F +2 readings to look at desired and actual timing those should be close to each other (if apart say more than .5 deg could be indication of stretched timing chain), since you have a T2 handy once it's good and warm try the time set command(which is different from TDC offset learn) desired time should go to 0 degrees and actual avg should be around 3.5 deg it may stagger at 3.5 deg avg actual, if it dies as soon as you hit time set command, timing is too far retarded. Which injectors you looking at stock or HO, before going HO you need to talk to him about gauges and reflash.

HO injectors IMO is last piece of the power building equasion, mine did not "wake up" until the PCM got reflashed. And this bit of advise DO NO MODS THAT ALTER FUEL OR BOOST DELVERY WITHOUT GAUGES