So the car is a LT1 Stingray and it is pulling negative timing at idle. It also has some random miss fires that I am hoping is related to the timing issue (changed plugs and wires already). We added long tube headers and a ported throttle body. Since there is no kr I'm guessing the ECM is just pulling timing to bring the idle down from the ported tb? Any other ideas on what it could be?
If it is an issue with the tb does anyone have any good ideas for adjustments? Should I bump up the throttle area limits a little bit? Its the stock size but it is ported. I've switched between two ported units and it didn't change anything. The original was sent back as a core already.
Should I bump the idle up a bit?