In my opinion this application is an extremely severe application at fairly high RPM at WOT for extended periods of time and I put this in place as a simple safety. The engine is accelerating quickly all the way to the limiter rpm since there is little load holding the engine back. So there is likely a significant amount of overshoot, where none of the cylinders are firing yet still getting fuel injected. If this happens for long enough I imagine the cylinders get flooded and will no longer fire.
I think there are a few ways to try and fix this:
- Remove timing in the tune right below the spark cut limiter to reduce torque (aka. acceleration) of the engine to lower the amount of overshoot. This is the easiest thing to test and see if it improves the situation.
- Program a timing adder to the code to do the same thing as above. There are likely many ways to implement something like this, but one I can thing of would have the user enter a timing modifier amount (eg. -5 Degrees) and an engine rpm before the limiter (eg. 100 rpm) to start applying that timing modifier. This would be possible, but still require a significant amount of work.
- Program a PID function to the spark cut to try and limit the amount of time all cylinders are being cut. I would also try to rotate through the cylinders being cut to try and limit the same cylinders being cut in a row for many times. This could still cause the same problem if most of the cylinders are being cut to hold the desired rpm. This would be quite complex and I'm not confident I could even do it.
- Program both option 2 & 3 to have a smoother cut and still be able to reduce torque. Obviously the most complex to implement, but also it would likely be the best working solution.
- Program some sort of staged injector cut to reduce the engine torque. I'm not a big fan of this as there will still be a small amount of fuel that would cause a lean burn
I actually started a thread a while ago about trying to make Launch Control smoother, but it could also be applied to the Engine Speed Limiter. It wasn't a priority to fix at the time because it was working for me fine as is. Creating a Smoother Launch Control