Group 25 Intake and Exhaust System Design and Function
Engines without Preheater
On engines not equipped with a preheater, engine
coolant temperature determines the point at which fuel
injection begins while starting. The crankshaft rotates an
extra number of turns to increase cylinder temperature
before fuel injection begins. This gives more reliable
starting and reduces exhaust emissions during cold
starts down to about –15
C(5
F). This means that the
crankshaft may need to rotate about 3–4 rotations before
fuel injection begins and the engine fires.
An exhaust pressure governor is activated during start-
up.
10
To Next Page
Loading...
