2008 Polaris Sportsman 700/800/700 X2 EFI Service Manual, Page 120Get this manual
FUEL INJECTION ELECTRONIC FUEL INJECTION
Principal Components
The Electronic Fuel Injection (EFI) system is complete engine fuel and ignition management designThis system includes the following principal components: Fuel Pump Fuel Rail Fuel Line(s) Fuel Filter(s) Fuel Injectors Pressure Regulator Throttle Bodylntake Manifold Engine Control Unit (ECU) Ignition Coils Coolant Temperature Sensor Throttle Position Sensor (TPS) Crankshaft Position Sensor (CPS) Intake Air Temperature and Barometric Air Pressure Sensor (T-BAP) Wire Harness Assembly Check Engine Light (MIL) 23When the intake valve opens, the fuelair mixture is drawn into the combustion chamber, ignitedand burnedThe ECU controls the amount of fuel being injected and the ignition timing by monitoring the primary sensor signals for air temperature, barometric air pressure, engine temperature, speed (RPM), and throttle position (load)These primary signals are compared to the programming in the ECU computer chip, and the ECU adjusts the fuel delivery and ignition timing to match the valuesDuring operation the ECU has the ability to re-adjust temporarily, providing compensation for changes in overall engine condition and operating environment, so it will be able to maintain the ideal airfuel ratioDuring certain operating periods such as cold starts, warm up, acceleration, etc richer airfuel ratio is automatically calculated by the ECU