Truck retarding timing???

[mean05]

yeah it's caused by TM or the motor itself seeing knock...you can pull up to 15° of timing...i have seen them go into negative timing before

[dropem]

well how could u tell if the motor is seeing knock?

[mean05]

well how could u tell if the motor is seeing knock?

hook up Ryans laptop to is and scan it...watch the scan and see what it does...you can always email me the scan also and i can take a look at it...being turbo'd your main spark table is prob in the 15 degree area and also another factor is IAT's, the higher the IAT's the more timing it will pull....i say go log it and see what it's doing, that will give you the best idea of whats going on