ENGINE EG 75 General This engine uses the D-4 (Direct injection 4-stroke gasoline engine) system. A (low pressure) fuel pump located inside the fuel tank pumps fuel to the high-pressure fuel pump located in the cylinder head cover. Then, the fuel is boosted to a pressure between 4 and 13 MPa in accordance with the driving conditions, and sent to the high-pressure fuel injectors. To enhance cold starting performance, a (low pressure) cold start fuel injector is provided in the surge tank. A fuel returnless system, which controls the fuel pressure for the low pressure side by way of a pressure regulator installed in the fuel tank, is used. However, the leak fuel from the high-pressure fuel pump and the fuel from the relief valve return to the fuel tank. To prevent fuel from leaking during a collision (in which air bags are deployed), a system that turns OFF the circuit opening relay is used to ensure safety. Fuel Pump (High Pressure) Cold Start Fuel Injector * Charcoal Canister Delivery Pipe(Right) Fuel Pump(Low Pressure) High-Pressure Fuel injector *:Only U.S.A. and Canada Delivery Pipe(Left) Fuel Tank A4270036P Direct injection 4-stroke Gasoline Engine (D-4) The D-4 (Direct injection 4-stroke gasoline engine) directly injects highly pressurized fuel into the cylinders. This engine effects comprehensive control of the fuel injection timing, air-fuel ratio, throttle valve position, etc., to realize both a high power output and low exhaust
EG 76 ENGINE emissions. The high-pressure slit nozzle injector atomizes fuel into a fine mist while expanding it to form a large, fan-shaped pattern. Then, the fuel mist enters the combustion chamber while drawing in a large volume of air. The fuel mist that is sprayed at high pressure expands into the combustion chamber on its own energy, without depending on the air current. Thus, it mixes efficiently with the intake air in order to achieve ideal combustion in all driving ranges. Injector Direct injection 4-stroke Gasoline Engine(D-4) A4270037P Air Fuel Ratio Control One of the two independent straight ports contains an SCV (Swirl Control Valve), which opens and closes to enhance both charging efficiency and combustion efficiency. When the engine is operating at low speed and low load conditions, the SCV remains fully closed. Thus, only one port is used for intake, in order to promote the mixture of air and fuel. This also accelerates the intake flow speed, which enhances combustion and improves fuel economy. When the engine is operating at high load conditions, the SCV opens to allow the intake of air through both straight ports. This increases the intake air volume and improves charging efficiency. At the same time, this creates a vertical swirl current (tumble current) in the combustion chamber to promote the mixture of air and fuel, thus improving performance. Fuel is injected during the compression stroke immediately after cold-starting. This enables the catalyst to warm up quickly, resulting in a dramatic reduction in exhaust emissions.
ENGINE EG 77 Intake Stroke Injection During Compression Stroke Ignition Conceptual image of fuel injection during cold starting A4270038P Fuel Pump A fuel pump assembly consisting of a (low pressure) fuel pump, fuel filter, and sender gauge is used. To prevent fuel from leaking during a collision (in which air bags are deployed), a system that turns OFF the circuit opening relay, in accordance with a signal from the airbag ECU, is used to ensure safety.
EG 78 ENGINE Fuel Pump Fuel Filter Pressure Regulator Sender Gauge A4270033P Fuel Pump Discharge Pressure [kpa] 400 Discharge Volume [L h] 190 Minimum Fuel Filter Filter System Paper Filter Type Filtering Surface Area [cm 2 ] 1550 Fuel Pump Control When the starter signal is ON and the engine speed signal is input continuously for 2 seconds or longer, the circuit opening relay turns ON to actuate the fuel pump. A fuel cut control is adopted to stop the fuel pump when the airbag is deployed at the front or side collision. In this system, the airbag deployment signal from the airbag sensor assembly is detected by the ECM, which turns OFF the circuit opening relay. After the fuel cut control has been activated, turning the ignition switch from OFF to ON cancels the fuel cut control, thus engine can be restarted.
ENGINE EG 79 IG Switch +B Main Relay Circuit Opening Relay IGSW MREL FC ECM Front Air Bag Sensor LH Side Air Bag Sensor LH +SL -SL VUPL SSL+ FSL SSR- +SR -SR VUPR SSR+ FSR SSR- Front Air Bag Sensor RH Side Air Bag Sensor RH Fuel Pump Relay FPR Gateway ECU Air bag ECU Fuel Pump CAN BEAN A4270034P Jet Pump The jet pump operates as described below. A jet pump is adopted in the fuel tank. Since the propeller shaft is located below its center bottom, the fuel tank of the GS430 is shaped as indicated below. A fuel tank with such a shape tends to cause the fuel to be dispersed into both chamber A and chamber B when the fuel level is low, stopping the fuel in chamber B from being pumped out. To prevent this from occurring, a jet pump has been provided to transfer the fuel from chamber B to chamber A. This is accomplished by utilizing the flow of the fuel, so that the vacuum created by the fuel, as it passes through the venturi is used to suck the fuel out of chamber B and send it to chamber A. Engine Pressure Regulator Return Fuel (From Pressure Regulator) Fuel Filter Venturi Fuel Pump From Chamber B Chamber B Jet Pump Chamber A Chamber B Chamber A A4270039P Fuel Sender Gauge To accurately inform the driver of the residual fuel volume in the saddle-shaped tank, inline sender gauges are provided in the two chambers, A and B. These sender gauges output the residual fuel volume of both chambers to the meter ECU. Based on the signals received from the two sender gauges and the SFI control information received from the ECM, the meter ECU calculates the residual fuel volume, and activates the fuel gauge.
EG 80 ENGINE Meter ECU F E Fuel Gauge Injection Volume Information Gateway ECU ECM Low Fuel Level Warning Light CAN BEAN Chamber A Fuel Tank Chamber B A4270040P Fuel Pump (High Pressure) This fuel pump is a highly efficient, single-plunger type in which the drive torque has been reduced. In addition, a solenoid spill valve and a check valve have been integrated to achieve a lightweight and compact system. Also, a pulsation damper has been installed at the lowpressure fuel inlet. Mounted on the cylinder head cover, this fuel pump is driven by a cam that is provided at the rear end of the exhaust camshaft on the right bank of the engine. A heat insulator is provided on the surface of the fuel pump that mounts to the cylinder head cover in order to suppress the increase in fuel temperature. The ECM variably controls the fuel to a high pressure that suits the driving conditions. Because this system uses a solenoid spill valve to control and discharge only the necessary volume of fuel, the drive torque and noise have been reduced. A fuel pressure sensor, which is provided in the fuel delivery pipe, gives feedback to the ECM in order to maintain an optimal fuel pressure at all times. This system varies the high fuel pressure between 4 and 13 MPa to suit the driving conditions, in order to reduce friction loss. A tapered seal metal joint is used for joining the high-pressure fuel delivery pipes. It consists of a solenoid spill valve that regulates the discharge volume of high-pressure fuel, a plunger that is driven by the camshaft and pressurizes fuel, and a check valve that mechanically opens and closes the passage to the fuel delivery pipe. A pulsation damper is provided at the low-pressure fuel inlet from the fuel tank, in order to reduce the pulsation of fuel.
ENGINE EG 81 Solenoid Spill Valve Low Pressure Fuel (From Fuel Tank) Return Fuel (To Fuel tank) Fuel Pump (High Pressure) Pulsation Damper Pressure Regulator(400kPa) High-Prussure Fuel (To Fuel Delivery Pipe) Pulsation Damper Delivery Pipe(LH) High-Pressure Fuel Injector Solenoid Spill Valve Delivery Pipe(RH) High-Pressure Fuel Injector ECM Fuel Pressure Sensor Fuel Filter Relief Valve (15.3MPa) Fuel Tank Check Valve(60kPa) Fuel Pump (High Pressure) Jet Pump Feed Pump Camshaft A4270041P High Pressure Fuel Pump Operation The plunger in the pump moves up and down to pressurize fuel. The solenoid spill valve, which is provided at the suction side of the pump, closes at an optimal timing during the compression stroke in order to control the fuel to the required pressure and volume. If the solenoid spill valve closes at an early timing, the effective stroke of the plunger becomes longer, thus pressurizing the fuel to an even higher pressure. The fuel that has been pressurized by the plunger pushes open the check valve (60 kpa), flows into the fuel delivery pipe, and is controlled to a pressure between 4 and 13 MPa (approximately 40 to 130 bars). The fuel pressure sensor that is provided on the fuel delivery pipe detects the fuel pressure and gives feedback to the engine ECU, enabling the engine ECU to control the fuel to a target pressure.
EG 82 ENGINE Plunger Lift 0 Solenoid Spill Valve Open Solenoid Spill Valve Close Valve Opening Pressure Control Solenoid Spill Valve Return Plunger Check Valve To Delivery Pipe Suction Freewheeling Pumping A4270236P Delivery Pipe An aluminum alloy fuel delivery pipe is used. A fuel pressure sensor and a relief valve are provided on the fuel delivery pipe. An injector clamp is provided to each area of the fuel delivery pipe where a high-pressure fuel injector is installed. This clamp applies a constant spring force to the injector to prevent the injector from moving when the combustion pressure is applied to the injector while the engine is being started, during which the fuel pressure is low. As a result, it increases the sealing performance of the injector, while reducing vibration and noise. O-rings and backup rings* are used in the areas in which the high-pressure fuel injectors and high-pressure fuel delivery pipes are joined. This reduces the transmission of the operating sounds of the high-pressure fuel injectors, enhances quiet operation, and ensures the sealing performance of the joined areas. REFERENCE *:The backup ring is provided to securely support the rubber O-ring, which is exposed to high fuel pressure. During assembly, make sure to install it with the correct position and orientation.
ENGINE EG 83 Backup rings Backup rings O-ring O-ring Backup rings 3 Fuel Pipe Backup rings 3 O-ring O-ring Delivery Pipe(RH) Backup rings 3 Fuel Pressure Sensor O-ring Injector Clamp Gasket Gasket High-Pressure Fuel Injector Delivery Pipe(LH) Relief Valve A4270043P Relief Valve A relief valve is provided in the fuel delivery pipe. When the fuel in the fuel delivery pipe increases to a predetermined pressure (15.3 MPa), the relief valve returns the fuel to the fuel tank. Fuel Delivery Pipe Fuel exit Sectional view A4270044P Injector A single-orifice, high-pressure slit nozzle injector is used. The injector atomizes fuel into a fine mist and expands it to form a large, fan-shaped pattern. Then, the fuel mist enters the combustion chamber while drawing in a large volume of air. This increases the intake air volume and improves charging efficiency. Furthermore, the intake air forms a vertical swirl current (tumble current) in the combustion chamber to promote the mixture of air and fuel, thus achieving high performance and a high power output. Because the injector is exposed inside the combustion chamber, a special coating has been applied to the nozzle in order to suppress the adhesion of carbon deposits created by the combustion gas. An insulator is used in the area in which the injector comes in contact with the cylinder head, and a Teflon shaft seal is used for sealing the injector against the cylinder pressure in order to reduce vibration and noise and enhance sealing performance. An EDU (Electronic Driver Unit) is used in order to operate the high-pressure fuel injectors speedily and precisely.
EG 84 ENGINE Insulator Nozzle Teflon Shaft Seal High-Pressure Fuel Injector Cross-Sectional Diagram A4270032P Fuel Injector Number of Orifices 1 Orifice Dimensions [mm] 0.15 0.71 Injection Pressure [MPa] 4 ~ 13 Cold Start Fuel Injector A cold-start fuel injector is used for improving cold-starting performance. It is provided in the surge tank of the intake manifold and injects fuel when the engine is started at low engine coolant temperature. Cold Start FuelInjector Number of Orifices 2 Flow Rate [cm 3 /min.](at300±1.5kpa) 120±12.0 Operating Conditions Engine Coolant Temperature At the time of low water temperature
ENGINE EG 85 Surge Tank Cold Start Fuel Injector Cross-Sectional Diagram Cold Start Fuel Injector A4270277P EDU(Electronic Driver Unit) An EDU to operate the high-pressure fuel injectors at high speeds is placed in the engine compartment. The EDU converts the injection request signal received from the ECU into high-voltage, high-amperage injector actuation signals, in order to actuate the high-pressure fuel injectors. EDU Operation EDU Operation (Circuit Diagram 1) When the ECM sends injection signals (IJt-1 to IJt-6) to the EDU, the COM terminal outputs a high voltage for actuating the injectors. When the injectors open the voltage switches to 12V to keep the injectors open. The current will flow from INj#+ to INj#- and to GND, in order to actuate the high-pressure fuel injectors. The control circuit constantly monitors the actuating state of the injectors, and sends an IJf fail signal to the ECM when the INj-# is actuated normally.
EG 86 ENGINE (Circuit Dgram 1) EDU FP+ INj6+ +B High Voltage Generating Circuit INj3+ INj5+ INj2+ INj4+ INj1+ ECM IJt-1 IJt-4 IJt-2 IJt-5 IJt-3 IJt-6 IJf Control Circuit INj1- INj4- INj2- INj5- INj3- INj6- High-Pressure Fuel Injector FPD FPF FP- Solenoid Spill Valve GND A4270045P Example of IJt-1 Actuation (Circuit Diagram 2) The fuel injection request signal IJt-1 from the ECM passes through the waveform shaping circuit, and separates into the monostable circuit - high side switch and the driver circuit. Then, the high side switch applies the high voltage boosted by the DC-DC converter, in accordance with the fuel injection request signal, from the INj1+ and INj4+ terminal to the INj1- and INj4- terminals (injectors #1 and #4). In accordance with a signal received from the waveform shaping circuit, the driver circuit grounds the INj1- terminal in a timely manner, in order to control the fuel injection volume and injection timing of injector #1. Circuit Diagram 2 Noise Filter DC-DC Converter High Side Switch +B INj4+ INj1+ GND Charging Control ECM IJt-1 IJt-4 IJf Waveform Shaping Monostable Fail Detection Driver Stable Current INj1- INj4- A4270046P Fuel Tank The fuel tank is mounted in the center of the vehicle, forward of the rear axle. It has a capacity of 71.0 liters.
ENGINE EG 87 The fuel tank adopts a saddle shape to allow the propeller shaft to pass through its center portion. Two sender gauges (main, sub), fuel pump, fuel filter, pressure regulator, and jet pump have been integrated. Fuel draining marks have been provided on the bottom of the fuel tank. These marks clearly indicate the position for aligning the fuel draining device during dismantling, and simplify and ensure the reliable draining of fuel. Fuel Draining Marks Fuel Tank Bottom View A4270047P Plastic Fuel Tank A fuel tank made of plastic is used for weight reduction. It consists of six layers of plastic to ensure the long life of the tank and the low permeation of fuel. HDPE Tank Exterior Tank Interior In-Process Recycled Material Adhesion Layer Barrier Layer Adhesion Layer HDPE *HDPE(High Density Polyethylene):High Density Polyethylene It is lightweight, high strength,and excels in water and solvent resistance. Layer Composition of Fuel Tank A4270048P
EG 88 ENGINE Charcoal Canister Canister purge control is used to draw the fuel evaporative gas created in the fuel tank into the intake port, to be burned during combustion. The charcoal canister is mounted behind the fuel tank. An internal pressure control valve is provided at the fuel passage inlet from the fuel tank in order to maintain the proper pressure in the fuel tank. Charcoal Canister Pump Module From Fresh Air Line To Intake Manifold Refueling Valve From Fuek Tank A4270049P