flyback signal - Thinking about MJ4
Posted: Sat Sep 12, 2009 5:57 am
Consider a COP setup but operating as a wasted spark system (ie firing in pairs).
Can you tell from the flyback signal from the individual coils - whether you have:
(a) Sparked under compression or sparked in an open cylinder?
(b) Not managed to spark at all?
If you can do (a) then you could start out (cranking) firing in pairs, then sense which one is doing the work and thence switch to normal COP firing of individual plugs in order to achieve higher rev limits - and all without a cam position sensor
If you can do (b) as well then how about an output saying 'you have a misfire on coilpack X' - in COP this would give you an amazing diagnostic tool, and it would be pretty damn useful with wasted spark too. A detected misfire could also be used to trigger a return to wasted spark operation to prevent the system getting totally out of phase.
Of course this all may be fantasy if nothing can be gleaned from the signal - in which case I am sorry to have wasted your time..
Roger
Can you tell from the flyback signal from the individual coils - whether you have:
(a) Sparked under compression or sparked in an open cylinder?
(b) Not managed to spark at all?
If you can do (a) then you could start out (cranking) firing in pairs, then sense which one is doing the work and thence switch to normal COP firing of individual plugs in order to achieve higher rev limits - and all without a cam position sensor
If you can do (b) as well then how about an output saying 'you have a misfire on coilpack X' - in COP this would give you an amazing diagnostic tool, and it would be pretty damn useful with wasted spark too. A detected misfire could also be used to trigger a return to wasted spark operation to prevent the system getting totally out of phase.
Of course this all may be fantasy if nothing can be gleaned from the signal - in which case I am sorry to have wasted your time..
Roger