IMHO, ECU control fuel & spark timing
It detects air by AFM, MAP, etc & inject fuel according to the programmed air fuel ratio
And it checks with knock sensor & oxygen sensor
Then it adjust the fuel & spark timing accordingly
VTEC, VVT, etc has another set of programming n sensors
This is from my knowledge la. I could be wrong
---------- Post added at 01:19 PM ---------- 6 hour anti-bump limit - Previous post was at 12:54 PM ----------
ECU didn't detect a bigger spark. It just detect knock & oxygen
If it detect knock, it will inject more fuel & retard spark timing
If it detect less oxygen, it will inject lesser fuel & advance spark timing
In the case of bigger spark, the oxygen has been burn completely..
So, ECU will reduce the fuel & u'll get better FC
I stand corrected![]()
Agree with this. Besides burning more completely and the ECU injecting less fuel, the increase response and torque will also result in less throttle input giving better FC.