PDI stands for petrol direct injection. It utilizes high-pressure fuel pumps and specialized injectors to deliver atomized gasoline directly into the engine cylinders. This allows for higher compression ratios, improved fuel economy, and precise control over the combustion event, though it eliminates the valve-cleaning wash effect of traditional port injection.
The carbon buildup on the intake valves is severe, which is typical for these early PDI engines.
Because the fuel never washes over the intake valves, engines with direct injection require regular mechanical or chemical carbon cleaning to maintain airflow.
Also heard as
- petrol direct injection
- direct injection
Related terms
GDI
Gasoline Direct Injection is a fuel delivery system that sprays gasoline directly into the combustion chamber.
PFI
This fuel delivery design positions the injectors just upstream of the intake valves.
EFI
Electronic Fuel Injection is a computer-controlled system that atomizes fuel into the engine.
Intake valve
A mechanical valve in the cylinder head that opens to allow air into the combustion chamber.