High-pressure fuel pump
Raises fuel pressure for direct injection.
Mounted on the engine on direct-injection applications.
Mechanical drive and controlled metering supply the fuel rail at the pressure requested by engine management.
A second pump preparing a much stronger spray.
Long starts, pressure faults or reduced power need supply-side checks before replacement.
Plugs and filters use engine-specific service guidance. Pumps and injectors are normally assessed through pressure, leakage and electrical tests.
Spark-plug service is usually less involved than direct-injector or high-pressure-pump replacement; coding and access can add work.
BMW high-pressure pump fitment differs between petrol and diesel systems and among engine families.
BMW combustion models; spark components are petrol-only and glow-plug hardware is diesel-only.