Chrysler RAM TRUCK 2500 1994 Service Manual page 958

• FUEL SYSTEM 14 - 17
FUEL TRANSFER PUMP CAPACITY TEST—DIESEL
ENGINE
For fuel pump capacity tests, refer to the Diesel
Engine —General Diagnosis section of this group.
FUEL TUBES/LINES/HOSES AND CLAMPS—LOW-
PRESSURE TYPE
Refer to Fuel Tubes/Lines/Hoses and Clamps. Also
refer to the section on Quick-Connect Fittings. These
can be found i n the Fuel Delivery—Except Diesel sec­
tion of this group.
QUICK-CONNECT FITTINGS
Refer to Quick-Connect Fittings. These can be
found i n the Fuel Delivery—Except Diesel section of
this group.
HIGH-PRESSURE FUEL LINES
CAUTION: The high-pressure fuel lines must be
held securely in place in their holders. The lines
cannot contact each other or other components. Do
not attempt to weld high-pressure fuel lines or to
repair lines that are damaged. Only u s e the recom­
mended lines when replacement of high-pressure
fuel line is necessary.
High-pressure fuel lines deliver fuel under pressure
of up to approximately 120,000 kPa (17,405 PSI)
from the injection pump to the fuel injectors. The
lines expand and contract from the high-pressure
fuel pulses generated during the injection process. All
high-pressure fuel lines are of the same length and
inside diameter. Correct high-pressure fuel line usage
and installation is critical to smooth engine opera­
tion.
WARNING; U S E E X T R E M E CAUTION WHEN IN­
S P E C T I N G F O R H I G H - P R E S S U R E F U E L L E A K S . IN­
S P E C T F O R H I G H - P R E S S U R E F U E L L E A K S WITH A
S H E E T O F C A R D B O A R D . HIGH F U E L INJECTION
P R E S S U R E CAN C A U S E P E R S O N A L INJURY IF
CONTACT IS MADE WITH T H E SKIN.
For removal and installation procedures, refer to
the Diesel Engine —Component Removal/Installation
section of this group.
INTAKE MANIFOLD AIR HEATER
The intake manifold air heater is controlled by the
powertrain control module (PCM). Refer to the Diesel
Engine—Component Description/System Operation
section of this group for an operational description.
Refer to the Diesel Engine—General Diagnosis sec­
tion for diagnosis. Refer to the Diesel
Engine—Component Removal/Installation section for
removal/installation procedures.
INTAKE MANIFOLD AIR HEATER RELAYS
The relays for the intake manifold air heater are
controlled by the powertrain control module (PCM).
Refer to the Diesel Engine—Component Description/
System Operation section of this group for an opera­
tional description. Refer to the Diesel
Engine—General Diagnosis section for diagnosis. Re­
fer to the Diesel Engine—Component Removal/Instal­
lation section for removal/installation procedures.
INTAKE MANIFOLD AIR TEMPERATURE SENSOR
The intake manifold air temperature sensor is con­
trolled by the powertrain control module (PCM). Re­
fer to the Diesel Engine sections of this group for an
operational description, diagnosis and removal/instal­
lation procedures.
FUEL INJECTION PUMP
The fuel injection pump is a Bosch P7100 series in­
line type (Fig. 9). The injection pump is driven by the
engine camshaft. A gear on the end of the pump shaft
meshes with the camshaft gear. The pump is timed
to the engine. Fuel injection occurs near the end of
the compression stroke for each cylinder.
DEUVERY OIL FILL PLUG
Fig. 9 Fuel Injection Pump
The RQV-K governor (Fig. 10) has a pump timing
feature. This will allow the pump shaft to be oriented
in a position corresponding to top dead center (TDC)
for the compression stroke of cylinder number one.
Indexing the governor flyweight assembly to the
shaft during assembly establishes pump timing.
As engine speed increases, the internal pump pres­
sure increases. An air-flow control (AFC) (Fig. 10) on
the governor ensures that regulated fuel delivery is
matched to intake manifold pressure (turbocharger