Page 236 - 05. Subyek Teknik Mesin - Automobile Mechanical and Electrical Systems Automotive Technology Vehicle Maintenance and Repair (Vehicle Maintenance Repr Nv2) by Tom Denton

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220 Automobile mechanical and electrical systems

Figure 2.286 Pipes and injectors

Figure 2.287 Common rail injection. (Source: Bosch Media)

effectively the same thing. Diesel engine injection timing is equivalent to the
ignition timing for petrol engines. Injection timing must fall within a narrow angle
of crankshaft rotation. It is advanced and retarded for engine speed and load
conditions. Injection timing is set by accurate positioning of the fuel injection
pump. Incorrect timing leads to power loss. An increase in the production of NO
x
when too far advanced, or an increase in the hydrocarbon emissions when too
far retarded, can occur.
Particulate emissions result from incomplete combustion of fuel. Particulates
are seen as black carbon smoke in the exhaust under heavy load or when fuel
delivery and/or timing is incorrect. White smoke may also be visible at other
times, such as when the injection pump timing is incorrect. It also occurs when
compression pressures are low or when coolant has leaked into the combustion
chambers.
Key fact Recent developments in electronic diesel fuel injection control have made it

Diesel engines are particularly possible to produce small direct injection engines ( Fig. 2.287 ). Diesel engines are
suitable for turbocharging. built to withstand the internal stresses, which are greater than in other engines.
Diesel engines are particularly suitable for turbocharging, which improves power
and torque outputs.