Dodge ram truck 3500 1996 Service Manual page 1239

BR FUEL S Y S T E i 14 - 5
DESCRIPTION AND OPERATION
(Continued)
FUEL TANK
All models pass a full 360 degree rollover test
without fuel leakage. To accomplish this, fuel and
vapor flow controls are required for all fuel tank con­
nections.
All models have a pressure relief/rollover valve
mounted in the top of the fuel tank.
An evaporation control system is used to reduce
emissions of fuel vapors into atmosphere by evapora­
tion and to reduce unburned hydrocarbons emitted
by vehicle engine. When fuel evaporates from fuel
tank, vapors pass through vent hoses or tubes to a
charcoal canister. The are temporarily held in the
canister. When the engine is running, the vapors are
drawn into intake manifold. Refer to Group 25, Emis­
sion Control System for additional information.
FUEL INJECTORS—3.9L/5.2L/5.9L ENGINES
The fuel injectors are attached to the fuel rail (Fig.
4). 3.9L engines use six injectors. 5.2L and 5.9L
engines use eight injectors.
FUEL
INJECTOR J9214-30
Fig. 4 Fuel Injectors—3.9L/5.2L/5.9L Engines-
Typical
The nozzle ends of the injectors are positioned into
openings in the intake manifold just above the intake
valve ports of the cylinder head. The engine wiring
harness connector for each fuel injector is equipped
with an attached numerical tag (INJ 1, INJ 2 etc.).
This is used to identify each fuel injector with its
respective cylinder number.
The injectors are energized individually in a
sequential order by the powertrain control module
(PCM). The PCM will adjust injector pulse width by
switching the ground path to each individual injector
on and off. Injector pulse width is the period of time
that the injector is energized. The PCM will adjust
injector pulse width based on various inputs i t
receives.
FUEL INJECTORS—8.0L ENGINE
The fuel injectors are attached to the fuel rail (Fig.
5). Ten individual injectors are used on the 8.0L
V-10 engine.
E L E C T R I C A L MOUNTING
CONNECTOR BOLTS (6)
Fig. 5 Fuel Injectors—8.0L Engine—Typical
The nozzle ends of the injectors are positioned into
openings in the intake manifold just above the intake
valve ports of the cylinder head. The engine wiring
harness connector for each fuel injector is equipped
with an attached numerical tag (INJ 1, INJ 2 etc.).
This is used to identify 'each fuel injector with its
respective cylinder number.
The injectors are energized individually in a
sequential order by the powertrain control module
(PCM). The PCM will adjust injector pulse width by
switching the ground path to each individual injector
on and off. Injector pulse width is the period of time
that the injector is energized. The PCM will adjust
injector pulse width based on various inputs it
receives.
FUEL RAIL—3.9L/5.2L/5.9L ENGINES
The fuel rail supplies the necessary fuel to each
individual fuel injector and is mounted to the intake
manifold (Fig. 6). The fuel pressure regulator is no
longer mounted to the fuel rail on any engine. I t is
now located on the fuel tank mounted fuel pump
module. Refer to Fuel Filter/Fuel Pressure Regulator