Programmed fuel injection

Programmed Fuel Injection, or PGMFI/PGM-FI, is the name given by Honda to a proprietary digital electronic fuel injection system for internal combustion engines which injects the right amount of fuel per cylinder based on specific engine data, available since the early 1980s. This system has been implemented on motorcycles, automobiles, and outboard motors.

With its origins beginning with the CX500 and CX650 turbocharged motorcycles in 1982 and 1983, respectively, Honda's PGM-FI made its way into their automobiles in the early 1980s with the ER engine equipped City Turbo. The system gained popularity in the late 1980s in their Accord and Prelude models with A20A, A20A3 & A20A4 engines (Honda A engine), and its motorcycles later on. In 1998, Honda built its third motorcycle with fuel injection; the VFR800FI.

The Engine Control Unit (ECU) has sensors which measure the temperatures of the engine, coolant, oil, and outside air as well as pressure sensors to monitor oil and barometric pressure. Based on these readings and the location of the throttle, the ECU calculates how much oxygen and fuel should be mixed for optimal and efficient performance.

...
Wikipedia