Introduction; Fuel Injection Pump - Yanmar 2TNV70 Service Manual

FUEL SYSTEM

INTRODUCTION

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This section of the Service Manual describes the
procedures necessary to remove, install, and time
the ML fuel injection pump and its associated
system components. This fuel injection pump is
representative of the fuel injection pumps used on
other TNV IDI model engines.

Fuel Injection Pump

Note: If the ML fuel injection pump itself
requires servicing, it must be taken to an
authorized Yanmar FIE (Fuel Injection
Equipment) repair facility.
The following describes the features of the ML fuel
injection pump, manufactured by Yanmar.
The fuel injection pump is a very important
component of the engine. It is capable of making
very precise fuel delivery adjustments according to
the varied loads applied to the engine.
All of the fuel injection pump components are very
precisely machined. It is extremely important to
follow good service practices and maintain
cleanliness when servicing the fuel injection pump.
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Figure 7-1
The Yanmar ML Fuel Injection Pump is an in-line
type pump which consists of a fuel supply plunger
(Figure 7-1, (1)) for each cylinder, a camshaft
(Figure 7-1, (2)), and a pump housing
(Figure 7-1, (3)). A delivery valve (Figure 7-1, (4))
connects to a high-pressure fuel line for each
cylinder. The fuel injection pump housing contains
a governor (Figure 7-1, (5)).
Fuel from the fuel tank to the fuel injection pump is
delivered by a low-pressure electric fuel pump. On
a few special models, a mechanical fuel pump is
used instead of an electric pump. The mechanical
fuel pump is mounted to the fuel injection pump
housing in place of the cover plate
(Figure 7-1, (6)).
Fuel to be injected into the cylinders is pressurized
by the up and down motion of each
camshaft-driven plunger, and is then supplied by
the high-pressure fuel lines to the respective fuel
injector.
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TNV IDI Service Manual
Introduction
0002238