What is the purpose of the small vacuum port on the bottom driver's side of the throttle body. It looks like it leads to an orifice just behind one of the throttle plates. can/should I plug it? The motor is in my hot rod so no vent canisters etc.

How much authority does the ECM have over ign. timing? If the initial timing is off by a few degrees will the ECM compensate?

Thanks
Bud

 

The little tiny nipple on the bottom of the tb is for the EVAP canister. If you have no EVAP canister, then you can block it off. As for timing, the ECM controls the advance/retard timing. Without the ECM controlling the timing, you can have detonation and or bad gas milage.