Teledyne Continental Motors, Inc.
TM
Engine
Description
2-2.7.2. Fuel Injectors
The fuel injector assembly is threaded on both ends and is made up of two parts: the
control coil and the injector (Figure 2-15). The internal components of the fuel injector
consist of a pintle valve and a spring. The solenoid creates an electromagnetic field to lift
the pintle valve and open the path for fuel to flow. The solenoid coil fits over the pintle
valve body. A support bracket is fitted on top of the solenoid to strengthen the electrical
wiring harness. A single jam nut secures the injector, solenoid and bracket assembly. The
valve design and injector end forms a self atomizing feed for the fuel, therefore, no air
bleeds are needed to assist in fuel atomization.
Fuel is supplied to the fuel injector via steel tube fuel lines that terminate at the injectors
using a ball seal and B-nut arrangement. The control channel in the ECUs of the FADEC
System controls fuel flow through the fuel injector by switching electrical current ON
and OFF to the control coil of the fuel injector assembly. When the current is ON, fuel
flows through the injector. The ON time for a given injection event is referred to as the
“injection duration.” The control channel receives information from the FADEC System
sensors and uses this information to determine the appropriate injection duration for the
next air intake cycle.
Each control channel will independently vary cylinder injection duration depending on
current engine operating conditions. At the appropriate crank rotation angle, the control
channel will command its injector open for the required injection duration to deliver the
appropriate amount of fuel for the combustion event. When the FADEC System detects
the need for more fuel to be injected to a given cylinder, the solenoids are held ON
(OPEN) for a longer duration permitting more fuel to flow into that given cylinder. The
amount of time the injector is held in the ON state determines how much fuel is delivered
to the cylinder.
WASHER
INJECTOR BODY
COIL BODY
LEAD WIRE
FUEL LINE
RETAINING NUT
TIE STRAP
SUPPORT
WASHER
INJECTOR BODY
COIL BODY
LEAD WIRE
FUEL LINE
RETAINING NUT
TIE STRAP
SUPPORT
Figure 2-15.
Fuel Injector Nozzle
IOF-240 Series Engine Maintenance Manual
2-17
31 August 2007
Change 1