SAFARI

ENGINE 9 Unique CR Strategies l Individual Injector Characterization ( I 2C) l Accelerometer Pilot Control (APC) l Cylinder balancing : Strategy to balance engine speed difference between cylinder to cylinder by modifying fuel delivery Cyclic variations during flywheel rotation maintained minimum by monitoring flywheel speed continuously l Anti-Oscillation Strategy (AOS): Strategy to prevent engine speed oscillations (Derivability) Fuel delivery is slewed based on various inputs like rpm, pedal position, engine temperature etc. Jerks during sudden accelerations minimised l Minimised individual injector spread on engine l Minimised injector drift over lifetime l Control of smallest pilot injection quantities over lifetime l Better control of multiple injection l The accelerometer strategy is based on the detection of the MDP (Minimum Drive Pulse) which generates combustion l MDP is the pulse required to inject the smallest fuel quantity Why APC l Running in of Injectors - possible injector drift l MDP changes due to physical tolerances l Constantly update MDP to maintain same fuel quantity over lifetime Opearation APC compensates possible injection quantity drift by: l actively monitoring this drift on vehicle and applying a compensation equal to the difference with the nominal for every injection Advantages l Small pilot quantities are under control l Enhanced diagnostic and engine protection against fuel supply system failure. l No vehicle dispersion for noise and emissions l No vehicle drift during vehicle life for noise and emissions l Driveability in transient is improved due to a better pressure regulation Note: l The pilot pulse is increased until a knock sensor signal is detected l Knock sensor “listens” to combustion noise from each cylinder separately l ECU updates MDP every 60 minutes Precautions: l Bleeding shouldnot bedoneby looseningHPpipes l HPpipes are one time use only – avoidunnecessary removal l Do not leave inlets and outlets of CR components exposed to dirt – Cap immediately l Flushing of CR components should not be done l It will introduce dirt l Do not remove battery connectionwhen key is ON l Do not spray water on the ECU l Sensor connections should not be removed unnecessarily l HP pipes should not be bent and force should not be applied l Fallenor brokenCRcomponents shouldnot beused l Avoid entering Test bed while engine is running at high speed and high load as any high pressure leakagemay cause injury l Monitor battery voltage continuously - recharge battery if voltage drops below10Volts l I 2C values must be entered correctly according to cylinder order l Drainwaterfromfilterandsedimenteratregularintervals Individual Injectors Characterisation ( I 2 C) Manufacturing tolerances of injector components: l Scattering of fuel delivery and opening delay from injector to injector l I 2C (16 digit code) for correcting the fuel delivery and opening delay l Exact defined injection quantity l Equals injection quantity from injector to injector l Important to achieve future emission legislation levels l Manufacturing process control Precaution I 2C values must be fed in correct cylinder order.Wrong entry will lead to unwanted engine vibrations and noise Accelerometer Pilot Control strategy (APC) What is Accelerometer l Accelerometer is a Knock Sensor which listens to Combustion knock