Fuel injector
Both port and direct injectors deliver fuel. Where does each one put the spray?
Meters and sprays fuel into the engine’s air supply or combustion chamber.
A port injector sprays into an intake port; a direct injector sprays into the combustion chamber. Their locations and hardware differ.
A port injector sprays into the intake port. A direct injector is installed in the cylinder head and sprays into the combustion chamber.
The engine controller operates the injector valve. Fuel pressure and opening time determine delivery; direct and port systems use different pressures and hardware.
Poor spray, leakage or an electrical fault may cause rough running, fuel-trim faults or starting difficulty. Fuel pressure and wiring also need consideration.
Think it throughAn image shows an injector, but does not establish the complete vehicle application. What should you locate in the system diagram before deciding whether it is port or direct injection?
Show the reasoning
Locate where the fuel leaves the injector relative to the intake port and combustion chamber. Use its documented system application; a photo of one injector is not proof of the layout in another vehicle.
- Classify injection by where the fuel is delivered.
- Check pressure, control and application in context.