Doosan DX60R Shop Manual page 352

Cold Start Device
The TNV model engines are equipped with a cold start device
(CSD).
The cold start device is located in the upper section of the fuel
injection pump and is connected to the engine°Øs cooling
system.
• The cold start device improves engine starting at
lower temperatures. At engine cooling system
temperatures below 41°F (5°C), the cold start device
advances the fuel injection timing and slightly
increases the fuel injection volume.
• For approximately the first 5 minutes of operation,
the idle speed of the engine will be slightly elevated.
Allow the engine to warm-up for at least five
minutes and the idle speed of the engine to return
to normal before engaging the transmission or
any PTOs. Engaging the transmission or PTO at
an elevated engine speed could result in an
unexpected movement of the equipment.
• When the cold start device is activated, you may
notice a slight increase in the exhaust smoke of the
engine during engine warm-up.
Electronically controlled engines 4TNV98-E use a
cold start device (CSD) that consists of a fuel
injection pump complete with a solenoid valve (1,
Figure 246).
• When the engine is started with the cooling water
sensor detecting a low water temperature of 10Ae 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.
Engine
Page 172
CAUTION
Figure 246
SP001693