A cylinder often misfires

[ESPER]

In today’s test, during operation at 6500rpm, one cylinder frequently misfired (the air-fuel ratio suddenly increased). I tried to replace the ignition coil and spark plug, and also tried to adjust the ignition Angle, but this phenomenon still occurs. In the operation process, it is normal for a period of time, but it will suddenly happen, and the reduction of speed can not be alleviated, and can only be stopped and restarted. Ask each senior, how should I check?
2025_0330_2012.emuprolog (669.5 KB)
Be on fire.emupro (27.4 KB)

[mkuklis_ECUMASTER]

What is the maximum speed allowed for the EMU pro 8

You have misfires at the end of the log. Trigger looks good at that point. I think the spark plugs get fouled. You are running very rich, and the injector’s pulse width is very chaotic. There are jumps of pulse width from 8.8 ms to 9.8 ms. That is 13% of fuel change at steady state conditions. That should not be happening. Two variables contribute to this. Manifold pressure and volumetric efficiency. Since this is a two-cylinder engine, the pulses in the intake are clearly visible. In t…