Mar 24, 2023
Here is how Toyoto did Port Fuel Direct Injection on 4 cylinders:
Toyota Direct Injection? Port Injection? Why Not Both?
Port fuel injection and direct fuel injection systems each have their advantages and disadvantages.Toyota calls this system the D-4S or Dynamic Force Engine
The direct fuel injectors are just like any other direct fuel injection system. And, the port fuel injectors are not there to clean the intake valves; these injectors work to provide fuel to the engine. Both sets of injectors work together for the best possible fuel mixture in the cylinder.
Port fuel injection can offer better vaporization under certain conditions.
Toyota uses its blended approach of port and direct fuel injection to give the best possible performance, emissions and economy.
D-4S Engines The latest vehicle to get it is the four-cylinder used in the 2017 Camry. The best way to spot one of these engines is to look for port fuel injectors and a high-pressure fuel pump.
How It Works
According to Toyota, during low-to-medium engine loads, both direct-type and port-type fuel injection are used together, or one of them is used to create homogeneous mixed air and fuel, thus contributing to stable combustion processes.
During high engine load ranges, only the direct-type fuel injection is used to cool down the intake air with the chilling effect of vapors in the fuel, which is injected into the cylinder, improving charge efficiency and anti-knock properties. Under some conditions, the intake valves open to allow the homogeneous air/fuel mixture into the combustion chamber, and fuel is injected during the first half of the intake stroke.
During a cold start, the system times the opening of the port and direct fuel injector to decrease emissions and achieve stratified combustion. Immediately after a cold engine start and during the exhaust stroke, fuel is injected into the intake port from the fuel injector assembly (for port injection). Fuel is also injected from the direct fuel injector near the end of the compression stroke. This results in an air-fuel mixture that is stratified, and the area near the spark plug is richer than the rest of the air/fuel mixture. This process allows a retarded ignition timing to be used, raising the exhaust gas temperature. The increased exhaust gas temperatures promote rapid warmup of the catalysts and improve exhaust emission performance.
It is impossible to detect where the changeover from port to direct injection occurs. The only way to see the different fuel injection operations is with a scan tool.
The ECM controls the fuel pump and calculates low-pressure fuel demand based on vehicle state and the signals sent from various sensors and outputs signals. Three-phase Pulse Width Modulation (PWM) control is used for the fuel pump control ECU.
Both injector sets use the same fuel pump in the tank to provide fuel pressure to the fuel rail for the port fuel injectors and the high-pressure fuel pump on the engine. The pump should produce 51 to 73 psi while running and five minutes after the engine has turned off. If the pump is not working, both systems will not work.
The high-pressure fuel pump can generate 435 to 725 psi.
The system offers the best of both worlds while avoiding carbon buildup on the intake valves. Other manufacturers, including Audi and even Ford, are adopting the Toyota D-4S dual-injection system. As the costs of the components decrease, look for these types of systems on even more engine applications.
Since Ford is using this system on 2024 Mustang 2.3L ,when will Bronco have Port Fuel Direct Injection to help with carbon issurs?
See pic below.
Toyota Direct Injection? Port Injection? Why Not Both?
Port fuel injection and direct fuel injection systems each have their advantages and disadvantages.Toyota calls this system the D-4S or Dynamic Force Engine
The direct fuel injectors are just like any other direct fuel injection system. And, the port fuel injectors are not there to clean the intake valves; these injectors work to provide fuel to the engine. Both sets of injectors work together for the best possible fuel mixture in the cylinder.
Port fuel injection can offer better vaporization under certain conditions.
Toyota uses its blended approach of port and direct fuel injection to give the best possible performance, emissions and economy.
D-4S Engines The latest vehicle to get it is the four-cylinder used in the 2017 Camry. The best way to spot one of these engines is to look for port fuel injectors and a high-pressure fuel pump.
How It Works
According to Toyota, during low-to-medium engine loads, both direct-type and port-type fuel injection are used together, or one of them is used to create homogeneous mixed air and fuel, thus contributing to stable combustion processes.
During high engine load ranges, only the direct-type fuel injection is used to cool down the intake air with the chilling effect of vapors in the fuel, which is injected into the cylinder, improving charge efficiency and anti-knock properties. Under some conditions, the intake valves open to allow the homogeneous air/fuel mixture into the combustion chamber, and fuel is injected during the first half of the intake stroke.
During a cold start, the system times the opening of the port and direct fuel injector to decrease emissions and achieve stratified combustion. Immediately after a cold engine start and during the exhaust stroke, fuel is injected into the intake port from the fuel injector assembly (for port injection). Fuel is also injected from the direct fuel injector near the end of the compression stroke. This results in an air-fuel mixture that is stratified, and the area near the spark plug is richer than the rest of the air/fuel mixture. This process allows a retarded ignition timing to be used, raising the exhaust gas temperature. The increased exhaust gas temperatures promote rapid warmup of the catalysts and improve exhaust emission performance.
It is impossible to detect where the changeover from port to direct injection occurs. The only way to see the different fuel injection operations is with a scan tool.
The ECM controls the fuel pump and calculates low-pressure fuel demand based on vehicle state and the signals sent from various sensors and outputs signals. Three-phase Pulse Width Modulation (PWM) control is used for the fuel pump control ECU.
Both injector sets use the same fuel pump in the tank to provide fuel pressure to the fuel rail for the port fuel injectors and the high-pressure fuel pump on the engine. The pump should produce 51 to 73 psi while running and five minutes after the engine has turned off. If the pump is not working, both systems will not work.
The high-pressure fuel pump can generate 435 to 725 psi.
The system offers the best of both worlds while avoiding carbon buildup on the intake valves. Other manufacturers, including Audi and even Ford, are adopting the Toyota D-4S dual-injection system. As the costs of the components decrease, look for these types of systems on even more engine applications.
Since Ford is using this system on 2024 Mustang 2.3L ,when will Bronco have Port Fuel Direct Injection to help with carbon issurs?
See pic below.
ResidualGenius
Last edited by a moderator:
Mar 24, 2023