Well maybe I thought wrong, but I thought that the computer learns the increase in air intake and then makes the adjustments in the right amount of fuel ratio. So is it not the air/fuel ratio combusted in the cylinder chamber. There for a good hot spark is needed to ignite that air/fuel in the chamber in order to explode the whole mixture, utilizing every bit of fuel, and making sure its all burned up. Thats why I was thinking of gapping just a little more. Thinking that the Little bit of fummy smell was fuel or left over gasses not being fully ignitied and there for wasted and coming out the exhaust pipe. Maybe I got it all wrong. either way I am going to try gapping a bit more. Remember my accel coil puts out 42,000 volts. I do run NGK v groove they have been good to me over the years.
i'm not saying don't gap it more, i'm saying that you don't control the mixture by gapping your spark plug, so if you want 12AFR you won't be reducing the gap or the other way around - if your optimal gap is 40 (just an example, i'm not saying that is in your case) then make it 40 regardless of what your AFR is or you want it to be.
the mixture doesn't explode btw (or shouldn't explode) when it does you get knocking, the mixture burns and that's why you need spark advance (before piston TDC) to give it time to burn completely, higher rpm requires more spark advance as the piston cycle time is reduced and the mixture will still burn in the same amount of time (controlled burn that is and not instantaneous as in an explosion)
what your computer learns is the fuel trims in closed loop, if you go with larger intake then you get more air and the computer (PCM) will compensate with more fuel based on the O2 feedback - it will always target 14.7 AFR so it will not be too rich. In open loop (usually WOT and/or under acceleration) you will not be richer than before with a larger intake and better flow but if there is a difference and you reach a limit it will be leaner, in this case (open loop) the 'puter uses a pre-loaded fuel map (table) based on operating parameters and it does not use your narrowband O2 sensor feedback. If your mixture is richer then you have too much fuel somehow, that can be a choked intake or larger injectors or higher fuel pressure. If you get unusual exhaust fumes it can be rich mixture, incomplete burn or burning oil.
In open loop at WOT where you'd be making top HP the computer uses your MAP reading and the rpm to calculate the amount of oxygen that is cycled thru a piston, the way you could see if there is a "choke" in the intake would be to take a reading of your map sensor output with the engine stopped and the key in "run" position (it would be basically reading the atmospheric pressure), then to a test on the road at WOT and take another reading - if they are the same then your intake has good flow, if the latter is lower (voltage that is) then your intake has some flow issues.
now, what your computer cannot read is the volummetric efficiency (VE) of your engine, what that means is that usually at wot and at high rpm the amount of air taken in the cylinder at the end of the piston intake stroke is less compared to the amount of air that would be in that cylinder with the engine stopped, so if out of the factory it is 85% VE at WOT and 5000rpm and you make a bunch of changes to your intake to increase the flow and the new VE is 90% your PCM will not know about it and will deliver the same amount of fuel as before - this is all in "open loop", in closed loop the mixture will be compensated by the PCM based on O2 feedback like i mentioned before.
