cb1100 startup sequence

[max]

Cool topic. I'm easily confused though. Since you're only looking at spark 1, how do you deduce that all sparks are firing initially?

Tommy if you look at the pulses in between spark 1 you see a smaller spark 2.
Remember we only have two coils for four cylinders so 1 ( and 4 ) marked fire together at the same time and 2 and 3 in between, they are all there but i only marked no 1 otherwise there is too much text in the picture.
Click on the picture for a bigger version if you like.

I don't have the wiring diagram handy, but don't we have a crankshaft position sensor (CKP I believe). That should play in somehow.

Max, can you provide a link to this device? I can't find it by searching.

Yup, cps on the right hand side behind the allen key cover;



But of course it rotates twice every fire cycle and is of no use to determine which cylinder to inject fuel to fire, you could be injecting on the combustion stroke instead of the intake stroke.
In most cars a camshaft sensor is used which rotates only once per fire cycle so the ecu knows when to inject fuel based on those 2 sensors, we only have a ckp sensor.

The h-scope is a build project based around an stm32 board like an arduino and connects to an android tablet with an "otg" cable, the stm32 uses 20 mA, peanuts.


https://www.youtube.com/watch?v=B_deBfrZiSI
https://www.youtube.com/watch?v=vhsX5kqz0Ws
https://www.youtube.com/watch?v=TdVszkCzRYE
https://github.com/martinloren/HScope/bl...210327.pdf

The project has two channels but i added 2 more with stereo potentiometers configured in an "H" per channel to maintain separation so i can add signals to channel 2 and select the amplitude of them to mix and identify which signal i am looking at ( the green trace ).
The voltage drop at startup just happened and was a nice bonus.

The injectors still had the resistors in 1 and 4 connector so i clipped the probes to those and clipped a sensor to sparkplug one for the timing reference.