Engine Control System 1A-17 Operation ECM calculates the basic injection amount optimum to the engine operating conditions and the maximum injection amount at that engine condition, compares and selects lower injection amount. By adding the phase compensated with the compensation ROM to that injection amount, the final injection amount is determined. At the time of start, the optimum fuel injection amount is determined by the starter signal and coolant temperature. (Injection amount increases more when the coolant temperature is lower.) 1. Basic injection amount Determined by accelerator opening and engine speed. 2. Max.
injection amount Maximum injection amount is determined by adding compensation by signals of sensors to the basic maximum injection amount (amount which can be theoretically injected) determined based on the engine speed. a. Intake air pressure compensation When the intake air pressure is high, the air amount is increased and the injection amount is increased. b. Intake air temperature compensation Injection amount is increased or decreased depending on the difference of density based on the intake air temperature. c. Fuel temperature compensation When the fuel temperature decreases, the injection amount is increased. d.
Coolant temperature compensation When the coolant temperature is lower, the injection amount is increased to secure the operability immediately after the cold start. 3. Injection amount compensation Since the actual injection amount decreases in comparison with the designated value of injection amount when the fuel temperature is higher, designated injection amount value is increased. Fuel Injection Timing Control Timing control valve is duty-controlled according to a signal from ECM (engine control module) to control the fuel injection start timing. Using the crankshaft angle feed back system, highly precise control is effected.
Accelerator Position Engine Speed Sensor Intake Air Pressure Sensor Sensor Increase When Higher Intake Air Temperature Sensor Basic Max. Injection Varying Depending on Amount Conditions Fuel Temperature Sensor Compen- Increases When Lower sation Coolant Temperature Sensor Increases When Lower Basic Injection Amount Max. Injection Amount Fuel Temperature Sensor Select Lower Injection Compensates to Increasing Amount Side Side When Higher Compen- sation Compensation ROM Compensation Value Injection Amount of Each Pump Determine EDU Electromagnetic Spill Valve LNW21AMF001001-X Com sat pen- ion