FUEL SYSTEM

Fuel Pump Assembly (for High Pressure)

1. The high-pressure fuel pump is constructed with a check valve that mechanically opens and closes the passage to the fuel delivery pipe and plunger that operate and pressurize the fuel by means of a intake camshaft LH and electromagnetic spill valve that regulate high-pressure fuel, and with a relief valve for when abnormal fuel pressure occurs. The electromagnetic spill valve, check valve and relief valve are integrated together, making the system lighter and more compact. A pulsation damper has been fitted to the low-pressure fuel intake from the fuel tank to reduce fuel pulsation.

2. The high-pressure fuel pump is attached to the camshaft housing sub-assembly LH and is driven by the cam attached to the front end of the intake camshaft.

3. Fuel is pressurized by the up-and-down motion of the pump plunger. An electromagnetic spill valve attached to the pump intake side closes with optimal timing during the pressurization process in order to maintain the required fuel pressure and fuel volume. If it closes too quickly, the plunger's effective stroke grows longer, resulting in higher fuel pressure.

4. Fuel pressurized by the plunger applies pressure on the check valve (60 kPa) to open it, transferring pressure to the fuel delivery pipe sub-assembly, and is regulated to between 2.4 and 20 MPa (approximately 24 to 200 atmospheres).

   

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   *1	Check Valve	*2	Spill Control Valve
   *3	Pulsation Damper	*4	Plunger
   *5	Fuel Injector Assembly (for Direct Injection)	*6	Fuel Delivery Pipe Sub-assembly (for Direct Injection)
   *7	Fuel Relief Valve	*8	Fuel Tank Assembly
   *9	Fuel Pump (for Low Pressure)	*10	Fuel Pressure Sensor
   *a	From Fuel Suction Tube with Pump and Gage Assembly (for Low Pressure)	*b	To Fuel Delivery Pipe Sub-assembly (for Direct Injection)
   *c	To Low-pressure Fuel System	-	-
   	Low-pressure Fuel		High-pressure Fuel

Fuel Delivery Pipe Sub-assembly (for Port Injection)

1. Stamped steel fuel delivery pipes are used for the fuel pipe sub-assembly (for port injection).

2. A fuel pressure pulsation damper assembly is mounted on the left and right delivery pipes respectively to reduce fuel pulsation.

3. A quick connector has been adopted for the connecting pipe between the left-hand and right-hand fuel delivery pipes to improve serviceability.

   

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   *A	Models with M/T for the Australia and New Zealand Packages	-	-
   *1	No. 1 Fuel Pipe Sub-assembly (for Port Injection)	*2	Fuel Pressure Pulsation Damper RH
   *3	Fuel Injector Assembly (for Port Injector)	*4	No. 2 Fuel Delivery Pipe Sub-assembly
   *5	Fuel Pressure Pulsation Damper LH	*6	No. 2 Fuel Pipe Sub-assembly (for Port Injection)
   *7	Clamp	-	-

Fuel Delivery Pipe Sub-assembly (for Direct Injection)

1. Carbon steel fuel delivery pipes are used for the fuel delivery pipe (for direct injection).

2. A fuel pressure sensor is installed on the fuel delivery pipe RH for direct injection.

3. A tapering seal metal fitting has been adopted for the connecting pipe between the left-hand/right-hand fuel delivery pipes, as well as from the high-pressure fuel pump to the left-hand fuel delivery pipe.

4. An injector clamp is provided for each area of the fuel delivery pipe where a fuel injector assembly (for direct injection) 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, the clamp increases the sealing performance of the injector, while reducing vibration and noise.

5. O-rings and backup rings are used in the areas in which the fuel injector assembly (for direct injection) and fuel delivery pipe (for direct injection) are joined. This reduces the transmission of the operating sounds of the fuel injector assembly (for direct injection), enhances quiet operation, and ensures the sealing performance of the joined areas.

   

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   *1	Fuel Pressure Sensor	*2	Fuel Delivery Pipe RH (for Direct Injection)
   *3	No. 1 Injector Holder	*4	Fuel Injector Assembly (for Direct Injection)
   *5	No. 2 Fuel Delivery Pipe	*6	Fuel Pump Assembly (for High pressure)
   *7	Fuel Delivery Pipe LH (for Direct Injection)	*8	Fuel Pipe

Fuel Injector Assembly (for Port Injection)

1. Compact and lightweight 12-hole injectors are used as fuel injectors for port injection.

2. Fuel consumption has been reduced and emission performance has been improved by facilitating the atomization of fuel and reducing fuel deposition on the intake port.

3. The nozzle has been extended to optimize the shape of the injection spray with the aim of improving fuel-air mixture formation.

   

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   *1	Injection Nozzle	-	-
   *a	Cross Section	*b	Bottom Side View

Fuel Injector Assembly (for Direct Injection)

1. High-pressure slit-nozzle injectors that have slit-shaped orifices for use as fuel injectors for direct injection have been adopted.

2. The fuel is atomized by these injectors, and it is injected into the combustion chamber while simultaneously spreading out like a fan and mixing with a large amount of air. By doing so, spatial dispersion of the injection spray is improved, achieving a homogeneous mixture while improving power and performance.

3. Because the injector is exposed to the inside of the combustion chamber, the end is treated with a special coating to prevent combustion gases from leaving deposits on it.

4. An insulator has been adopted for the area in which the injector comes in contact with the cylinder head, and a Teflon shaft seal has been adopted in the cylinder pressure seal, reducing vibration and noise while improving sealability.

5. The injectors are controlled through high-voltage and a constant-current control based on instructions from the ECM. This allows the injectors to inject high-pressure fuel in a short amount of time.

   

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   *1	Insulator	*2	Teflon Shaft Seal
   *3	Injection Nozzle	-	-
   *a	Cross Section	*b	Bottom Side View

Fuel Tank Assembly

1. A multi-layer plastic fuel tank is used. The multiplex layered plastic fuel tank consists of six layers of four types of materials, and one of those is a recyclable material to address environmental concerns.

2. A fuel drain mark has been provided at the lowest position of the fuel tank assembly. When dismantling (scrapping) the vehicle, drain fuel by drilling a hole at the drain mark.

   

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   *1	Fuel Tank Assembly	*2	High Density Polyethylene (HDPE)
   *3	Regrind Material	*4	Adhesive
   *5	Ethylene Vinyl Alcohol Copolymer (EVOH)	*6	Fuel Drain Mark
   *a	Fuel Tank Outside	*b	Fuel Tank Inside

3. The fuel tank uses a saddle shape to allow the propeller shaft to pass under the center portion of the tank. Also, a jet pump is used to transfer the fuel from the side of the tank without the fuel pump to the side with the fuel pump.

4. A fuel tank with such a shape tends to cause fuel to be present in both chamber A and chamber B when the fuel level is low. This stops 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.

5. This is accomplished by utilizing the flow of the fuel through the jet pump, so that the pressure difference, which is 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.

   

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   *1	Engine	*2	Fuel Tank Assembly
   *3	Chamber B	*4	Chamber A
   *5	Fuel Pump (for Low Pressure)	*6	Fuel Filter Assembly
   *7	Fuel Pressure Regulator Assembly	*8	Jet Pump
   *a	From Fuel Pump (Return)	*b	From Chamber B
   *c	To Chamber A	-	-