Fuel Injection System - Diesel: Operation: Injectors
The injection nozzles spray fuel into a prechamber as each compression stroke occurs. Nozzles can be disassembled, cleaned, and adjusted to correct improper spray patterns.
Injector opening pressure is adjusted with a shim on top of the needle valve return spring. See Fig 1 . The injector receives a high pressure pulse of fuel which forces open the needle valve allowing the fuel to pass into the prechamber.
The glow plug system uses 4 glow plugs (heaters) to assist in cold starting. When engine coolant is below 122°F (50°C), the No. 2 glow plug relay supplies full battery voltage to quickly heat the glow plugs.
When the glow plug reaches maximum temperature, relay No. 2 is turned off and relay No. 1 provides a reduced voltage to maintain glow plug temperature. When the engine starts, the glow plug system is turned off. See Figure .