Efi Overview; Efi Operation Overview - Polaris RZR PRO R Service Manual

EFI / FUEL SYSTEM

EFI OVERVIEW

EFI OPERATION OVERVIEW

The EFI system is designed to provide peak engine performance with optimum fuel efficiency and lowest possible
emissions. The ignition and injection functions are electronically controlled, monitored and continually corrected during
operation to maintain peak performance.
The central component of the system is the Bosch MG1 Electronic Control Unit (ECU) which manages system
operation, determining the best combination of fuel mixture and ignition timing for the current operating conditions.
An electric fuel pump is used to move fuel from the tank, through the fuel supply line, to the fuel rail. At the engine, fuel
fed through the fuel rail supplies fuel to the injectors, which inject into the intake ports. The ECU controls the amount of
fuel by varying the length of time that the injectors are "on." This range can vary depending on fuel requirements. The
controlled injection of the fuel occurs every other crankshaft revolution, or once for each 4-stroke cycle. When the
intake valve opens, the fuel/air mixture is drawn into the combustion chamber, ignited and burned.
The ECU controls the amount of fuel being injected and the ignition timing by monitoring the primary sensor signals for
intake air temperature, manifold absolute pressure (load), engine temperature, engine speed (RPM) and throttle
position. These primary signals are compared to the programming in the ECU computer chip, and the ECU adjusts the
fuel delivery and ignition timing based on these values.
During 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 air/fuel ratio. During certain 5
operating periods such as cold starts, warm up, acceleration, etc., a richer air / fuel ratio is automatically calculated by
the ECU.
9940259 R02 - 2022 RZR PRO R / PRO R 4 Service Manual
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