Bad Knock Sensor?

[EL PHAMTASMO]

Hey guys I'm new to the site and in need of some info. I have a 1999 Tahoe with the 5.7 vortec engine. I just replaced the engine and it does not seem to have the power it used to. I got an obdII cable and software for my laptop so I could better "see" what is going on. Everything looks O.K. but I am not sure about the timing advance. It is usually between 18 and 35 degrees, but under heavy load or going up the mountain it drops to 11 degrees or lower, and I have even seen negative numbers a time or two. I know the computer controls timing but I am not sure if this is normal. I have no experience with obdII vehicles, but I suspect my knock sensor may be at fault. Any help would be greatly appreciated.
Thanks

 

[TheBeast99]

that advancement sounds right to me. my scanner shows mine at 25 degrees while idling.

 

[EL PHAMTASMO]

Thanks Man, I was just curious. I love being able to hook my laptop up and actually "see" what the ecm "sees" from the sensors.

 

[tpricez71]

if your scanner will read cam retard, which is actually your timing on your distributor it should be set at zero. found out the other day mine was actually at -8. had a guy with a better scanner bring it up and we reset it to 0. i found this out from a gm tech who found it while checking my hoe out cause i keep setting lean codes. hoped this helps you.