COP ignition on Toyota Altezza

Checking the waveforms on this car, which was difficult to start and ran roughly. We wanted to eliminate possible electrical problems, as we suspected the head gasket was gone between cylinders 2 and 3. The red channel represents current consumption, the blue channel is the switching signal from the ECU to the coil, and the green channel is the HT trace from the plug firing.

Category:

Autos & Vehicles

Tags:

• Picoscope
• COP
• coil on plug ignition
• Toyota
• Alteeza

[RUSS16V2]

On a closer look at the end of the clip I was probably wrong with my first comment...

[matchudcu]

@RUSS16V2 This Altezza suddenly started running on 2 cylinders. We used a picoscope to eliminate electrical cause: The waveforms shown are all normal - red for coil current consumption, blue for ECU switching, and green is the HT spark. It turns out cylinders 2 and 3 had lost all compression. Look at 'Altezza with no compression on cylinders 2 and 3 for more information

[RUSS16V2]

So am I right in thinking that the number 2 COP was doing nothing? Ie not sparking?