Direct Petrol Injection System with Bosch Motronic MED 7 - Volkspage

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Engine management Engine torque implementation in the direct petrol injection system The engine control unit uses the internal and external torque requirements to compute the target torque and how it is to be implemented. Implementation in stratified charge mode In stratified charge mode, the target torque is implemented via the injection quantity. The air mass is of secondary importance because the throttle valve is wide open in order to reduce throttle losses. The ignition point is of little importance because of the retarded injection point. 253_110 Implementation in homogeneous lean charge mode and in homogeneous charge mode In both operating modes, the torque requirements are implemented in the short term via the ignition point and in the long term via the air mass. As the air-fuel mixture in both operating modes has a fixed lambda of 1.55 and 1 respectively, the injection quantity is predefined by the air mass and, therefore, is not used for torque control. 253_109 20
Intake system In comparison with the Bosch Motronic ME 7.5.10, the intake system has been adapted to meet the requirements of a direct petrol injection engine. The special thing about this system is that in-cylinder air flow is controlled depending on the operating mode. The modifications include: 1 a hot-film air mass meter (G70) with intake air temperature sender (G42) for more precise load sensing 2 an intake manifold pressure sender (G71) for calculating the exhaust gas recirculation rate 3 an intake manifold flap change-over mechanism (N316, G336) for selective air flow control in cylinder 4 an electric EGR valve (G212, N18) with a large cross-section for high exhaust gas recirculation rates 5 a brake servo pressure sensor (G294) for brake vacuum control 7 7 3 3 3 1 6 2 3 5 5 5 3 8 4 6 Throttle valve control unit (J338) 7 Activated charcoal canister system (N80) 8 Motronic control unit (J220) 253_079 21
Page 1 and 2: Service. Self-Study Programme 253 D
Page 3 and 4: Table of Contents Introduction . .
Page 5 and 6: Why has Volkswagen waited until now
Page 7 and 8: Homogeneous operation at high exhau
Page 9 and 10: Combustion process The term "combus
Page 11 and 12: Injection cycle Fuel is injected du
Page 13 and 14: Homogeneous lean charge mode This i
Page 15 and 16: Mixture formation process By inject
Page 17 and 18: Motronic control unit J220 Fuel pum
Page 19: Torque-based engine management syst
Page 23 and 24: This is how it works The driver inp
Page 25 and 26: Intake manifold flap actuated In st
Page 27 and 28: Air-mass flow meter G70 and intake
Page 29 and 30: This is how the exhaust gas recircu
Page 31 and 32: Fuel system The fuel system is divi
Page 33 and 34: This is how it works The fuel flows
Page 35 and 36: The fuel pressure regulating valve
Page 37 and 38: This is how it works Inlet with fin
Page 39 and 40: Activated charcoal canister system
Page 41 and 42: Exhaust system This was adapted to
Page 43 and 44: Broadband lambda probe (G39) The br
Page 45 and 46: Exhaust gas temperature sender (G23
Page 47 and 48: NOx sensor control unit (J583) This
Page 49 and 50: Function of the NOx sender The func
Page 51 and 52: Sulphur regeneration is a technical
Page 53 and 54: Variable valve timing Inner exhaust
Page 55 and 56: Positive terminal GND Input signal
Page 57 and 58: Notes 57 Solutions to questions on
Page 59 and 60: 5. What is the signal from the inta

Direct Petrol Injection System with Bosch Motronic MED 7 - Volkspage

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