08 Ignition Primary Current Testing

[@MuhammadAli-su3oo]

To see Primary Voltage waveform; we have to back probe -ve wire of a 3or4 Wire Coil-on-Plug?

[@medicfour9268]

It is impossible to see primary voltage on 3 or 4 wire coils. Because coil negative is inside the coil housing between the transistor and primary winding. It is possible to see current on feed and ground, and the computers signal to the transistor's base but no coil (-) voltage.

[@Discretesignals]

Great video! You should add coil turn off time as a possible cause of weak spark. You have to have a good scope to see it, but usually anything over 16 microseconds is not good.