2001 DODGE RAM Valve

(1) Clean area around overflow valve and fuel
return line at injection pump before removal.
(2) Remove valve from pump and banjo fitting.
(3) Discard old sealing gaskets.
INSTALLATION
The overflow valve (pressure relief valve) is located
at the outside of fuel injection pump (Fig. 60). It con-
nects the fuel return line (banjo fitting) to the pump.
The valve has no internal serviceable parts and must
be replaced as an assembly. Two sealing gaskets are
used. One gasket is located between pump and banjo
fitting. The other is located between the banjo fitting
and end of valve.
(1) Install new sealing gaskets to valve.
(2) Install valve through banjo fitting and into
pump.
(3) Tighten to 30 N´m (24 ft. lbs.) torque.
WATER IN FUEL SENSOR
DESCRIPTION
The WIF sensor is located on the side of the fuel
filter/water separator canister (Fig. 61).
OPERATION
The sensor sends an input to the Engine Control
Module (ECM) when it senses water in the fuel filter/
water separator. As the water level in the filter/sep-
arator increases, the resistance across the WIF
sensor decreases. This decrease in resistance is sent
as a signal to the ECM and compared to a high
water standard value. Once the value reaches 30 to
40 kilohms, the ECM will activate the water-in-fuel
warning lamp through CCD bus circuits. This all
takes place when the ignition key is initially put in
the ON position. The ECM continues to monitor the
input at the end of the intake manifold air heater
post-heat cycle.
REMOVAL
The Water-In-Fuel (WIF) sensor is located at the
side of fuel filter/water separator canister. Refer to
Fuel Filter/Water Separator Removal/Installation for
WIF sensor removal/installation procedures.
Fig. 60 Overflow Valve Location
1 - FUEL SUPPLY LINE
2 - FUEL RETURN LINE
3 - BANJO BOLT (TEST PORT FITTING)
4 - OVERFLOW VALVE
5 - BANJO FITTING
Fig. 61 Water-in-Fuel Sensor Location
1 - WATER-IN-FUEL (WIF) SENSOR
2 - FUEL FILTER/WATER SEPARATOR
3 - WIF SENSOR CONNECTOR
BR/BEFUEL DELIVERY - DIESEL 14 - 85
OVERFLOW VALVE (Continued)

FUEL DRAIN MANIFOLD
DESCRIPTION
The fuel drain manifold is actually a rifled passage
within the cylinder head (Fig. 62).
OPERATION
When the engine is running, and during injection, a
small amount of fuel flows past the injector nozzle and
is not injected into the combustion chamber. This fuel
is used to lubricate the fuel injectors. Excess fuel
drains into the fuel drain manifold (or passage). Fuel is
drained from this passage into a line at the rear of the
cylinder head (Fig. 62). After exiting the cylinder head,
fuel is routed (returned) back to the fuel tank. A ªTº is
installed into the fuel return line (Fig. 62). This ªTº is
used to allow excess fuel from the injection pump to be
returned into the fuel tank. A one-way check valve
within the overflow valve prevents fuel (from the fuel
drain manifold) from entering the fuel injection pump.
Asmallamount of fuel is returned from the fuel
injectors, while alargeamount (about 70% of sup-
plied fuel) is returned from the fuel injection pump.
REMOVAL
The fuel drain manifold (line) connects a fuel
return passage within the cylinder head to a ªTº fit-
ting on the fuel return line. It is located at the rear
of the cylinder head.(1) Disconnect both negative battery cables at both
batteries.
(2) Remove starter motor. Refer to Group 8B for
procedures.
(3) Disconnect fitting at ªTº (Fig. 63).
(4) Remove banjo bolt at rear of cylinder head.
Discard old sealing washers.
(5) Remove fuel line from vehicle.
(6) Clean connection at rear of cylinder head
before line installation.
INSTALLATION
The fuel drain manifold (line) connects a fuel
return passage within the cylinder head to a ªTº fit-
ting on the fuel return line. It is located at the rear
of the cylinder head.
Servicing fuel return components will not require
air bleeding.
(1) Using new sealing washers, assemble banjo
bolt to fuel line.
(2) Position line to engine and loosely tighten fas-
teners.
(3)
Tighten banjo bolt to 24 N´m (18 ft. lbs.) torque.
(4) Tighten fitting at ªTº to 12 N´m (106 in. lbs.)
torque.
(5) Install starter motor. Refer to 8, Starter for
procedures.
(6) Connect both negative battery cables at both
batteries.
Fig. 62 Fuel Drain Manifold Passage
1 - REAR OF CYLINDER HEAD
2 - BANJO FITTING/BOLT
3 - FUEL RETURN TO TANK
4 - FUEL RETURN LINES
5 - FUEL RETURN LINE FROM PUMP OVERFLOW VALVE
6 - FUEL DRAIN MANIFOLD PASSAGE
7 - ªTº
Fig. 63 Fuel Return Line at Rear of Cylinder Head
1 - REAR OF CYLINDER HEAD
2 - BANJO FITTING/BOLT
3 - FUEL RETURN TO TANK
4 - FUEL RETURN LINES
5 - FUEL RETURN LINE FROM PUMP OVERFLOW VALVE
6 - FUEL DRAIN MANIFOLD PASSAGE
7 - ªTº
14 - 86 FUEL DELIVERY - DIESELBR/BE

Fig. 1 Fuel System Components - Diesel
1 - ENGINE COOLANT TEMPERATURE (ECT) SENSOR 14 - FUEL SUPPLY LINE (LOW-PRESSURE, TO ENGINE)
2 - THROTTLE LEVER BELLCRANK AND APPS (ACCELERATOR
PEDAL POSITION SENSOR)15 - FUEL TRANSFER (LIFT) PUMP
3 - INTAKE MANIFOLD AIR HEATER/ELEMENTS 16 - OIL PRESSURE SENSOR
4 - HIGH-PRESSURE FUEL LINES 17 - FUEL FILTER/WATER SEPARATOR
5 - FUEL HEATER 18 - DRAIN TUBE
6 - FUEL PRESSURE TEST PORT 19 - WATER-IN-FUEL (WIF) SENSOR
7 - MAP (BOOST) SENSOR 20 - ENGINE CONTROL MODULE (ECM)
8 - FUEL INJECTORS 21 - FUEL PRESSURE TEST PORT
9 - FUEL INJECTOR CONNECTOR 22 - CAMSHAFT POSITION SENSOR (CMP)
10 - INTAKE AIR TEMPERATURE (IAT) SENSOR 23 - OVERFLOW VALVE
11 - FUEL DRAIN MANIFOLD 24 - FUEL INJECTION PUMP
12 - DRAIN VALVE 25 - FUEL HEATER TEMPERATURE SENSOR (THERMOSTAT)
13 - FUEL RETURN LINE (TO FUEL TANK)
14 - 88 FUEL INJECTION - DIESELBR/BE
FUEL INJECTION - DIESEL (Continued)

SPECIFICATIONS
TORQUE - DIESEL ENGINE
DESCRIPTION N m Ft. Lbs. In. Lbs.
Accelerator Pedal Position Sensor
Bracket Bolts12 105
Air Intake Housing Bolts 24 18
Banjo Fittings at top of Filter/Separator 24 18
Banjo Fittings at Fuel Return Lines 24 18
Banjo Fitting At Fuel Supply Line
(Injector Pump)24 18
Camshaft Position Sensor (CMP) Bolt 20 15
ECM Mounting Bolts 24 18
Engine Coolant Temperature (ECT)
Sensor14 10
Engine Lifting Bracket Bolts 77 57
Fuel Drain Manifold ªTº Fitting 12 106
Fuel Filter Canister Bracket Bolts 24 18
Fuel Filter Canister Mounting Nut 14 10
Fuel Filter Drain Valve Mounting
Screws3-5 30-40
Fuel Heater Screws 2-3 15-20
Fuel Injector Clamp Bolts 10 89
Fuel Pump Module Locknut 24-44 18-32
Fuel Tank Mounting Nuts 41 30
Fuel Transfer Pump Mounting Nuts 12 9
High-Pressure Fuel Line Fittings (at
Injectors)38 28
High-Pressure Fuel Line Fittings (at
Pump)24 18
High-Pressure Fuel Line Clamps-to-
Intake Manifold24 18
Hose Clamps at Intercooler Tube 8 72
Injection Pump-to-Injection Pump Gear
Nut170 125
Injection Pump Mounting Nuts 43 32
Intake Manifold Air Temperature (IAT)
Sensor14 10
Intake Manifold Air Heater Relay Bolts 4.5 40
Manifold Air Pressure (MAP) Sensor 14 10
PCM Mounting Bolts 4 35
Overflow Valve-to-Fuel Injection Pump 24 18
Water-In-Fuel (WIF) Sensor 2-3 15-20
14 - 90 FUEL INJECTION - DIESELBR/BE
FUEL INJECTION - DIESEL (Continued)

(1) Disconnect both negative battery cables at both
batteries.
(2) Remove cable cover (Fig. 6). Cable cover is
attached with 2 Phillips screws, 2 plastic retention
clips and 2 push tabs (Fig. 6). Remove 2 Phillips
screws and carefully pry out 2 retention clips. After
clip removal, push rearward on front tab, and
upward on lower tab for cover removal.
(3) Using finger pressure only, disconnect end of
speed control servo cable from throttle lever pin by
pulling forward on connector while holding lever
rearward (Fig. 7).DO NOT try to pull connector
off perpendicular to lever pin. Connector will
be broken.
(4) Using two small screwdrivers, pry throttle
cable connector socket from throttle lever ball (Fig.
7).Be very careful not to bend throttle lever
arm.
(5) Disconnect transmission control cable at lever
arm (if equipped). Refer to 21, Transmission.
(6) Squeeze pinch tabs on speed control cable (Fig.
7) and pull cable rearward to remove from cable
mounting bracket.
(7) Squeeze pinch tabs on throttle cable (Fig. 7)
and pull cable rearward to remove from cable mount-
ing bracket.
(8) If equipped with an automatic transmission,
refer to 21, Transmission for transmission control
cable removal procedures.
(9) Disconnect wiring harness clip (Fig. 8) at bot-
tom of bracket.
(10) Remove 6 mounting bolts (Fig. 8) and par-
tially remove APPS assembly from engine. After
assembly is partially removed, disconnect electrical
connector from bottom of sensor by pushing on con-
nector tab (Fig. 9).
(11) Remove APPS assembly from engine.
INSTALLATION
The APPS is serviced (replaced) as one assembly
including the lever, brackets and sensor. The APPS is
calibrated to its mounting bracket. The APPS assem-
bly is located at left-front of engine below plastic
cable/lever/linkage cover (Fig. 6).
(1) Snap electrical connector into bottom of sensor.
(2) Position APPS assembly to engine and install 6
bolts. Tighten bolts to 12 N´m (105 in. lbs.) torque.
(3) Connect wiring harness clip (Fig. 8) at bottom
of bracket.
(4) If equipped with an automatic transmission,
refer to Group 21, Transmission for transmission con-
trol cable installation procedures.
(5) Install speed control cable into mounting
bracket. Be sure pinch tabs (Fig. 7) have secured
cable.(6) Install throttle cable into mounting bracket. Be
sure pinch tabs (Fig. 7) have secured cable.
(7) Connect throttle cable at lever (snaps on).
(8) Connect speed control cable to lever by pushing
cable connector rearward onto lever pin while hold-
ing lever forward.
(9) Install cable cover.
(10) Connect both negative battery cables to both
batteries.
(11)ECM Calibration:Turn key to ON position.
Without starting engine, slowly press throttle pedal
to floor and then slowly release. This step must be
done (one time) to ensure accelerator pedal position
sensor calibration has been learned by ECM. If not
done, possible DTC's may be set.
(12) Use DRB scan tool to erase any DTC's from
ECM/PCM.
FUEL INJECTOR
DESCRIPTION
Six individual, high-pressure fuel injectors are
used. The injectors are vertically mounted (Fig. 10)
into a bored hole in the top of the cylinder head. This
bored hole is located between the intake/exhaust
valves.
Fig. 10 Fuel Injector Location
1 - CLAMP
2 - FUEL INJECTOR
3 - BORED HOLE
4 - SHIM
5 - BOLTS
BR/BEFUEL INJECTION - DIESEL 14 - 93
ACCELERATOR PEDAL POSITION SENSOR (Continued)

OPERATION
High-pressure fuel is supplied from the injection
pump, through a high-pressure fuel line, through a
steel connector and into the fuel injector. When fuel
pressure rises to approximately 31,026 kPa (4,500
psi), the needle valve spring tension is overcome. The
needle valve rises and fuel flows through the spray
holes in the nozzle tip into the combustion chamber.
The pressure required to lift the needle valve is the
nozzle opening pressure. This is sometimes referred
to as the ªpopº pressure setting.
Each fuel injector is connected to each high-pres-
sure fuel line with a steel connector (Fig. 11). This
steel connector is positioned into the cylinder head
and sealed with an o-ring. The connectors are sealed
to the high-pressure fuel lines with fittings (Fig. 11).
The ferrule (Fig. 11) on the end of the high-pressure
fuel line pushes against the steel connector when the
fuel line fitting is torqued into the cylinder head.
This torquing force provides a sealing pressure
between both the fuel line-to-connector and the fuel
connector-to-fuel injector.The fitting torque is
very critical.If the fitting is under torqued, the
mating surfaces will not seal and a high-pressure
fuel leak will result. If the fitting is over torqued, the
connector and injector will deform and also cause a
high-pressure fuel leak. This leak will be inside the
cylinder head and will not be visible. The result will
be a possible fuel injector miss-fire and low power.
The fuel injectors use hole type nozzles (Fig. 12).
High-pressure flows into the side of the injector and
causes the injector needle to lift and fuel to be
injected. The clearances in the nozzle bore (Fig. 12)
are extremely small and any sort of dirt or contami-
nants will cause the injector to stick. Because of this,
it is very important to do a thorough cleaning of any
lines before opening up any fuel system component.
Fig. 11 Fuel Injector Connections
1 - CONNECTOR
2 - O-RING
3 - FERRULE
4 - FITTING
5 - FUEL LINE
6 - INJECTOR
Fig. 12 Fuel Injector Spray Pattern
1 - INJECTOR
2 - CLEARANCE
3 - SHIM
4 - NOZZLE
Fig. 13 Fuel Injector Edge Filter
1 - EDGE FILTER
2 - FITTING
3 - FUEL INJECTOR
14 - 94 FUEL INJECTION - DIESELBR/BE
FUEL INJECTOR (Continued)

Always cover or cap any open fuel connections before
a fuel system repair is performed.
Each fuel injector connector tube contains an edge
filter (Fig. 13) that breaks up small contaminants
that enter the injector. The edge filter uses the injec-
tors pulsating high-pressure to break up most parti-
cles so they are small enough to pass through the
injector.The edge filters are not a substitute for
proper cleaning and covering of all fuel system
components during repair.
The bottom of each fuel injector is sealed to the
cylinder head with a1.5mmthick copper shim (gas-
ket) (Fig. 12). The correct thickness shim must
always be re-installed after removing an injector.
Fuel pressure in the injector circuit decreases after
injection. The injector needle valve is immediately
closed by the needle valve spring and fuel flow into
the combustion chamber is stopped. Exhaust gases
are prevented from entering the injector nozzle by
the needle valve.
DIAGNOSIS AND TESTINGÐFUEL INJECTOR
TEST
The fuel injectors are located in the top of the cylin-
der head between the intake/exhaust valves (Fig. 14).
A leaking fuel injector can cause fuel knock, poor
performance, black smoke, poor fuel economy and
rough engine idle. If fuel injector needle valve does
not operate properly, engine may misfire and produce
low power.
A leak in injection pump-to-injector high-pressure
fuel line can cause many of same symptoms as mal-
functioning injector. Inspect for leaks in high-pressure
lines before checking for malfunctioning fuel injector.
WARNING: THE INJECTION PUMP SUPPLIES HIGH-
PRESSURE FUEL OF UP TO APPROXIMATELY
120,000 kPa (17,400 psi) TO EACH INDIVIDUAL
INJECTOR THROUGH HIGH-PRESSURE LINES. FUEL
UNDER THIS AMOUNT OF PRESSURE CAN PENE-
TRATE SKIN AND CAUSE PERSONAL INJURY. WEAR
SAFETY GOGGLES AND ADEQUATE PROTECTIVE
CLOTHING. AVOID CONTACT WITH FUEL SPRAY
WHEN BLEEDING HIGH-PRESSURE FUEL LINES.
WARNING: DO NOT BLEED AIR FROM FUEL SYS-
TEM OF A HOT ENGINE. DO NOT ALLOW FUEL TO
SPRAY ONTO EXHAUST MANIFOLD WHEN BLEED-
ING AIR FROM FUEL SYSTEM.
(1) To determine which fuel injector is malfunc-
tioning, run engine and isolate each cylinder using
DRB scan tool.The DRB scan tool lists the injec-
tor firing order in both cylinder numerical
order (1±2±3±4±5±6), and actual firing order
(1±5±3±6±2±4).
(2) Note RPM drop for each cylinder. As an alter-
native, loosen high-pressure fuel line fitting at fuel
injector connector tube (Fig. 15). Listen for a change
in engine speed. After testing, tighten line fitting to
40 N´m (30 ft. lbs.) torque. If engine speed drops,
injector was operating normally. If engine speed
remains same, injector may be malfunctioning. Test
all injectors in same manner one at a time.
Fig. 14 Fuel Injector Connections
1 - CONNECTOR
2 - O-RING
3 - FERRULE
4 - FITTING
5 - FUEL LINE
6 - INJECTOR
Fig. 15 Inspecting Injector Operation
1 - HIGH-PRESSURE FUEL LINE
BR/BEFUEL INJECTION - DIESEL 14 - 95
FUEL INJECTOR (Continued)

(3) Once injector has been found to be malfunc-
tioning, remove it from engine and test it. Refer to
Fuel Injector Removal/Installation.
WARNING: FUEL INJECTOR TESTERS CAN
DEVELOP EXTREMELY HIGH PRESSURES. FUEL
UNDER THIS AMOUNT OF PRESSURE CAN PENE-
TRATE SKIN AND CAUSE PERSONAL INJURY.
WEAR SAFETY GOGGLES AND ADEQUATE PRO-TECTIVE CLOTHING. AVOID CONTACT WITH FUEL
SPRAY WHEN OPERATING INJECTOR TESTOR.
(4) After injector has been removed, obtain bench-
mount fuel injector tester OTCt(SPXt) part number
4210 (Fig. 16) (or equivalent). Install Special Tool
number 8301 (Fuel Injector Adapter) to 4210 tester.
Install fuel injector into 8301 adapter. Be sure tip of
adapter tool 8301 is aligned to inlet hole at side of
injector (Fig. 17) before tightening tool. Tighten tool
8301 to injector. Position container below injector
before testing.
(5) Refer to operating instructions supplied with
pressure tester for procedures.
(a) Check opening pressure or ªpopº pressure.
Pressure should be approximately 31,026 kPa (310
bars) or (4500 psi6250 psi). If fuel injector needle
valve is opening (popping) too early or too late,
replace injector.
(b) Perform a leak-down test on injector. Apply
pressure with injector tester. The injector should
not leak (drip) fuel with pressure at approximately
20 bars (291 psi) lower than pop pressure.
(c) Operate tester lever quickly several times to
check injector spray pattern. Verify fuel is spraying
from each injector nozzle hole. Injector should also
spray evenly from each nozzle hole.
(d) Pay attention to size and shape of spray
plumes. They should all be equal. If possible, com-
pare spray pattern to that of a new fuel injector
with same part number. Checking each plume for
consistency is an excellent indicator of injector per-
formance. Even if only one nozzle hole is plugged,
significant performance problems could result.
(e) Look for burrs on injector inlet.
(f) Check nozzle holes for hole erosion or plug-
ging.
(g) Inspect end of nozzle for burrs or rough
machine marks.
(h) Look for cracks at nozzle end.
(i) Check nozzle color for signs of overheating.
Overheating will cause nozzle to turn a dark yel-
low/tan or blue (depending on overheating temper-
ature).
(j) Look at end of injector tube where it meets
injector. A small, shiny band should be seen at this
point. The band should have a consistent thick-
ness. If not, injector could be leaking into fuel
return.
(k) If any of these conditions occur, replace injec-
tor.
REMOVAL
The fuel injectors are located in the top of the cyl-
inder head between the intake/exhaust valves (Fig.
18).
Fig. 16 Fuel
1 - FUEL INJECTOR
2 - ADAPTOR TOOL 8301
3 - POP PRESSURE TESTER
Fig. 17 Installing Injector to Adaptor Tool 8301
1 - ADAPTOR TOOL 8301
2 - TIP
3 - FUEL INJECTOR
4 - INLET AT SIDE OF INJECTOR
14 - 96 FUEL INJECTION - DIESELBR/BE
FUEL INJECTOR (Continued)