Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

System Description

DESCRIPTION
The injector is an injection nozzle with a solenoid valve which injects fuel according to the injection signal coming from the engine control module.

OPERATION
The injector has a fixed nozzle opening area and the fuel pressure against manifold inside pressure is regulated to a fixed level. Therefore, the volume of fuel injected by the injector is determined by the time during which the needle valve is open, namely, by the time during which the solenoid coil is energized.

The battery voltage is applied through the MFI relay to this injector. When the engine control module turns ON the power transistor in the unit, the solenoid coil is energized to open the injector valve, which then injects fuel.