Method And System For Predicting Trapped Air Mass In A Two-Stroke Engine

A method of operating a two-stroke engine comprising:

• determining a beginning time of a window for measuring fuel pressure;
• determining an ending time of the window;
• measuring fuel pressure between the beginning time and the ending time;
• determining a fuel pulsewidth based on the fuel pressure;
• and
• injecting fuel into the two-stroke engine in response to the pulsewidth.

A system comprising:

• a barometric pressure sensor generating a barometric pressure signal,
• a tuned pipe temperature generating a tuned pipe temperature signal;
• an engine speed sensor generating an engine speed signal;
• an intake air temperature sensor generating an intake air temperature signal;
• a two-stroke engine;
• a fuel system comprising a fuel pressure sensor, fuel temperature sensor and a fuel injector;
• and
• a controller in communication with the fuel pressure sensor, fuel temperature sensor, and controlling the fuel injector with a fuel pulsewidth determined by determining a trapped air mass estimation in response to the barometric pressure signal, the tuned pipe temperature signal the engine speed signal and the intake air temperature signal and generating a fuel pulsewidth in response to the trapped air mass estimation.