FUEL SYSTEM
7-10
TNV DI Service Manual
Introduction
Figure 7-2
• When the engine is started with the cooling water
sensor detecting a low water temperature of 10Åé
or lower and the E-ECU receives the
corresponding signal, then the E-ECU causes the
CSD's solenoid valve to increase the injection
rate and advance the injection timing.
• Because of this, the engine speed increases by
approximately 75 min-1 while the CSD is
operating. When the water temperature becomes
10°C or higher, the CSD is turned off and the
engine returns to the normal speed.
Trochoid Fuel Pump
Note: The trochoid fuel pump located on the
side of the MP fuel injection pump is not
a “fuel supply” pump. The function of this
pump is to raise the pressure of the fuel
supplied by the electric fuel supply pump
to the internal fuel pressure required by
the MP fuel injection pump.
The use of an electric fuel supply pump is required
on all TNV model engines with the MP fuel injection
pump.
Electronically controlled governor
Electronically controlled engines 4TNV84T-Z,
4TNV98-Z, 4TNV98-E, and 4TNV98T-Z are
quipped with an electronically controlled governor
called "Eco Governor". Combined with the rack
actuator (Figure 7-2, (3)), engine speed sensor
(Figure 7-2, (5)), and other parts, the electronically
controlled governor communicates with the engine
controller (E-ECU), whereby the engine speed and
fuel injection rate are controlled.
(1)
(2)
(3)
(4)
(5)
(6)
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