Fuel lines DODGE RAM 1999 Service Repair Manual

Fig. 6: Locating Intake Manifold Air Heater
Courtesy of Chrysler Corp.
NOTE: Restricted low-pressure fuel lines from fuel tank to fuel
transfer pump, fuel heater and fuel filter/water separator
may cause starting problems and prevent engine from
accelerating. Restricted high-pressure fuel lines from fuel
injection pump to fuel injector may cause starting problems,
poor engine performance and excessive Black smoke.
11) Check all fuel supply and returns lines for damage,
kinking or leakage. Check throttle linkage for binding. Check for a
stretched or disconnected throttle return spring.
12) Ensure all ground connections are tight and free of
corrosion. Ensure accessory drive belt is not damaged or slipping.
Check for loose or defective electrical connection on Crankshaft
Position (CKP) sensor. See Fig. 1.

13) On A/T models, ensure all electrical connectors are clean
and properly connected to electrical plugs on transmission case. On
all models, check for loose or defective electrical connections on
starter and starter solenoid.
MECHANICAL INSPECTION
Compression
Manufacturer does not provide information for checking
compression.
FUEL SYSTEM
AIR IN FUEL SYSTEM
NOTE: Air in the fuel system may cause hard starting, rough
running, excessive smoke, poor engine performance, engine
misfire, poor fuel economy and fuel knock. Air may enter fuel
system whenever fuel supply lines, fuel filter/water
separator, fuel injection pump, fuel injectors or high
-pressure fuel lines are removed or disconnected.
1) Inspect all low-pressure fuel lines from fuel tank to fuel
transfer pump, fuel heater and fuel filter/water separator for signs
of leakage. Inspect all high-pressure fuel lines for signs of leakage.
See FUEL INJECTOR & HIGH-PRESSURE FUEL LINES under FUEL SYSTEM.
2) After repairing fuel leak, bleed air from fuel system. See
FUEL LINE BLEEDING under FUEL SYSTEM in REMOVAL, OVERHAUL &
INSTALLATION - TRUCKS - DIESEL article.
FUEL HEATER
1) Fuel heater is located in fuel filter/water separator. See
Fig. 1 . Fuel heater uses a fuel heater temperature sensor for
controlling operation of the fuel heater.
2) A defective fuel heater may cause excessive wax build-up
in the fuel filter/water separator during cold ambient temperatures.
Wax build-up may cause hard starting, prevent engine from
accelerating, low power, Blue smoke or White smoke. For testing of
fuel heater and fuel heater temperature sensor, see SYSTEM & COMPONENT
TESTING - TRUCKS - DIESEL article.
FUEL HEATER RELAY
Ensure fuel heater relay, located in power distribution
center is installed correctly and that terminals are not corroded. For
fuel heater relay testing, see SYSTEM & COMPONENT TESTING - TRUCKS -
DIESEL article.
FUEL FILTER/WATER SEPARATOR
NOTE: A blocked or restricted fuel filter/water separator may cause
starting problems, prevent engine from accelerating, low
power or White smoke. If an excessive amount of water
collects in filter/separator in a short period of time, it
may be necessary to drain and clean fuel tank.
1) When ignition switch is first turned to ON position,
WATER-IN-FUEL (WIF) warning light should come on for 2 seconds to
perform bulb and wiring circuit test and then go off. WATER-IN-FUEL
(WIF) warning light is located on instrument panel, just below the

outlet port. See Fig. 7. Start engine. Outlet pressure should not be
more 5 psi (0.4 kg/cm) less than inlet pressure. If pressure drop is
more than 5 psi (0.4 kg/cm), replace fuel filter and retest pressure.
If pressure drop is less than 5 psi (0.4 kg/cm), check for fuel
supply restriction.
NOTE: Due to very small vacuum specifications, use a scan tool and
Periphal Expansion Port (PEP) module with 0-15 psi transducer\
to perform following test.
Fuel Supply Restriction Test
Ensure transfer pump pressure is okay. Disconnect fuel supply
line at fuel transfer pump inlet. Remove plastic clip from pump inlet
and install in end of fuel supply line. Install 3/8" Adapter Hose
(6631) between fuel supply line and pump inlet. Install transducer
from PEP module to "T" fitting on adapter. Connect scan tool to
module. Start engine. Check vacuum reading with engine at full
throttle with no load. If vacuum reading is less than 6 in. Hg, check
for fuel supply air leaks. If vacuum reading is 6 in. Hg or more,
check fuel line for damage, dents and kinks. Repair as necessary. If
no problem is found, remove fuel module from fuel tank and check for
obstructions. Repair as necessary.
NOTE: A 3' section of 1/4" I.D. clear tubing and a 1/8" NPT fitting
are required for the following test.
Fuel Supply Air Leak Test
Clean area around filter inlet fitting plug, then remove
plug. See Fig. 7. Install 1/8" NPT fitting with 1/4" nipple fitting in
test port. Attach clear hose with a clamp to fitting. Place other end
of hose in a fuel container. Turn ignition switch to START position,
then release to RUN position without starting engine. Fuel transfer
pump should run for 25 seconds. After hose has been purged, watch for
any air bubbles in hose. If no bubbles exist, system is okay. If
bubbles exist, check fuel line, fittings and fuel module in tank.
Repair as necessary.
OVERFLOW VALVE
1) Fuel transfer pump delivers more fuel to fuel injection
pump than needed. Surplus fuel is routed back to fuel tank by overflow
valve. Overflow valve is used to secure fuel return line to side of
fuel injection pump. See Fig. 1. A sticking check valve in the
overflow valve may result in low power. Pressure release is set at 14
psi. (1.0 kg/cm
). If outlet valve is stuck closed, a FTC may set.
2) Clean area around outlet valve and fuel return line.
Remove valve from pump and fitting. Using regulated air pressure, test
valve by blowing into valve inlet. Valve should open at 14-16 psi. (1.
0-1.1 kg/cm
). If valve does not open, replace valve. Reduce air
pressure to 10 psi. (0.7 kg/cm). Valve should close. If valve does
not close, replace valve. Using NEW gaskets, install valve through
banjo fitting into fuel injection pump. Tighten valve to 24 ft. lbs.
(30 N.m).
FUEL INJECTOR & HIGH-PRESSURE FUEL LINES
WARNING: DO NOT allow diesel fuel to contact hot engine when checking
fuel injector, as high exhaust temperatures could cause fire.
Use care when working around high-pressure fuel lines, as
fuel is under extreme pressure and could penetrate skin,
causing personal injury. Wear safety goggles and protective
clothing when checking fuel injectors.

NOTE: A leaking fuel injector or high-pressure fuel line may cause
a rough idle, Black smoke, poor engine performance, poor fuel
economy and fuel knock. Since a leaking high-pressure fuel
line may cause the same symptoms, check for leaking high
-pressure fuel line before checking fuel injector.
1) To determine which injector or line is malfuntioning,
start engine and check each cylinder output using scan tool. If scan
tool is not available, start engine and engine allow to idle. Loosen
high-pressure fuel line nut at each fuel injector in turn and listen
for a decrease in engine speed. Tighten high-pressure fuel line nut to
30 ft. lbs. (40 N.m). Go to next step.
2) To check for a leaking high-pressure fuel line, start
engine and allow engine to idle. Inspect high-pressure fuel lines and
connections for signs of fuel leakage by placing cardboard over high-
pressure fuel line and connection. Note if leak is being detected by
fuel being sprayed onto the cardboard. If leak exists, repair leak by
tightening high-pressure fuel line nut to 30 ft. lbs. (40 N.m) or
replacing high-pressure fuel line as necessary. If high-pressure fuel
line is replaced, bleed air from fuel system. See FUEL LINE BLEEDING
under FUEL SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - TRUCKS -
DIESEL article. If no leaks are found, go to next step.
3) Remove suspect injector. See FUEL INJECTOR under FUEL
SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - TRUCKS - DIESEL article.
Test injector with a diesel fuel injector tester. Follow tester
instructions. Replace fuel injector if fuel injector opening (pop)
pressure is not 4250-4750 psi (299-334 kg/cm
). Replace injector if
any leaks are noted at 291 psi (20 kg/cm) less than opening (pop)
pressure. Inspect injector for burrs, cracks, wear and plugging. Check
spray pattern. If any problems are noted, replace injector.
FUEL INJECTION PUMP TIMING
Improper fuel injection pump timing may result in low power,
excessive smoke and poor fuel economy. To check fuel injection pump
timing, see FUEL INJECTION PUMP TIMING in ADJUSTMENTS - TRUCKS -
DIESEL article.
INTAKE MANIFOLD AIR HEATER
NOTE: Intake manifold air heater is used to heat incoming air
before entering each cylinder. Warming of incoming air aids
in engine starting and improved driveability during cold
ambient temperatures. Engine Control Module (ECM) uses input
signals from various sensors for controlling intake manifold
air heater relays.
SUMMARY
If no faults were found while performing basic diagnostic
procedures, proceed to SELF-DIAGNOSTICS - JEEP, TRUCKS & RWD VANS
article. If no diagnostic trouble codes are found in self-diagnostics,
proceed to TROUBLE SHOOTING - NO CODES - DIESEL article for diagnosis
by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent
diagnostic procedures.

Minimum Compression Pressure
Dakota
2.5L ........................................................ (1)
3.9L, 5.2L & 5.9L ............................. 100 psi (690 kPa)\
Durango ........................................ 100 psi (690 kPa)\
Ram Pickup ..................................... 100 psi (690 kPa)\
Ram Van Ram Wagon .............................. 100 psi (690 kPa)\
Maximum Variation Between Cylinders ............................ ( 1)
( 1) - Information is not available from manufacturer.









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FUEL SYSTEM
FUEL PRESSURE RELEASE
WARNING: Fuel system is under high pressure. ALWAYS release fuel
pressure before attempting to open system for testing or
component replacement. DO NOT allow fuel to flow onto engine
or electrical parts while testing fuel system components.
Vehicles With Fuel Rail Test Port
1) Loosen fuel tank filler cap. Ensure ignition is off.
Remove protective cap from fuel rail test port.
2) Place one end of Fuel Pressure Release Hose (C-4799-1)
into an approved fuel container. Attach remaining end of hose to fuel
rail test port. Use care, as fuel system may be under pressure. Fuel
pressure will be released from fuel system. Remove hose, reinstall
protective cap, and fuel tank filler cap.
3) Wait 5 seconds. Use care when disconnecting fuel lines, as
some fuel pressure may still exist in fuel lines.
NOTE: One or more DTCs may set when fuel pump relay is removed.
Clear DTCs from PCM after fuel pressure release procedure. To
clear DTCs from PCM, see CLEARING DTCS under SELF-DIAGNOSTIC
SYSTEM in SELF-DIAGNOSTICS - JEEP, TRUCKS & RWD VANS
article.
Vehicles Without Fuel Rail Test Port
1) Remove gas cap. Using a non-metallic tool, open flapper
valve in filler neck to relieve pressure. Remove fuel pump relay from
Power Distribution Center (PDC). Relays are identified on label under
PDC cover. Start and run engine until it stalls. Attempt to start
engine. Continue restarting engine until it will no longer run. Turn
ignition off.
CAUTION: DO NOT supply power to fuel injector for more than 4 seconds,
or fuel injector may be damaged.
2) Disconnect any fuel injector connector. Connect a jumper
wire between either fuel injector terminal and positive battery
terminal. Connect another jumper wire to other fuel injector terminal.
Momentarily touch other end of jumper wire to negative battery
terminal.
3) Place a shop towel under fuel line quick-connector at fuel
rail. Use care when disconnecting fuel lines, as some fuel pressure
may still exist in fuel lines. Disconnect fuel line quick-connector.
Reinstall fuel pump relay in PDC. Clear DTCs from PCM. To clear DTCs
from PCM, see CLEARING DTCS under SELF-DIAGNOSTIC SYSTEM in SELF-
DIAGNOSTICS - JEEP, TRUCKS & RWD VANS article.
FUEL PRESSURE TEST

Fig. 3: Typical Thermostatic Air Cleaner System
FUEL EVAPORATIVE SYSTEM (EVAP)
The EVAP system allows for proper fuel system ventilation
while preventing fuel vapors from reaching the atmosphere. This means
that vapors must be caught and stored while the engine is off, which
is when most fuel evaporation occurs. When the engine is started,
these fuel vapors can be removed from storage and burned. In most
systems, storage is provided by an activated charcoal (or carbon)
canister. See Fig. 4. On a few early systems, charcoal canisters are
not used. Instead, fuel vapors are vented into the PCV system and
stored inside the crankcase.
The main components of a fuel evaporation system are a sealed
fuel tank, a liquid-vapor separator and vent lines to a vapor-storing
canister filled with activated charcoal. The filler cap is normally
not vented to the atmosphere, but is fitted with a valve to allow both
pressure and vacuum relief.
Although a few variations do exist between manufacturers,
basic operation is the same for all systems. Check for presence of
vapor storage canister or crankcase storage connections when required.
Ensure required hoses, solenoids, etc., are present and connected
properly. Check for proper type fuel tank cap. Check for any non-OEM
or auxiliary fuel tanks for compliance and the required number of
evaporation canisters.

TROUBLE SHOOTING
NOTE: To trouble shoot mechanical engine components, see
appropriate table in TROUBLE SHOOTING article in GENERAL
INFORMATION.
REMOVAL & INSTALLATION
CAUTION: When battery is disconnected, vehicle computer and memory
systems may lose memory data. Driveability problems may exist
until computer systems have completed a relearn cycle. See
COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION
before disconnecting battery.
NOTE: For installation reference, label all electrical connectors,
vacuum hoses and fuel lines before removal. Also place mating
marks on engine hood and other major assemblies before
removal.
FUEL PRESSURE RELEASE
CAUTION: Fuel system is under pressure. Pressure must be released
before servicing fuel system components.
Gasoline
1) Disconnect negative battery cable. Loosen fuel tank cap to
release tank pressure. Press on filler tube flap to relieve any
additional tank pressure.
NOTE: Fuel filler tube has spring-loaded flap located below fuel
fill cap to serve as secondary seal if fuel fill cap is not
tightened. It is part of EVAP monitor system when vehicle is
equipped with leak detection pump (LDP). Vehicle may be
equipped with flap installed into fuel filler tube even if
vehicle is NOT equipped with LDP and EVAP monitor system.
2) Remove fuel pump relay from Power Distribution Center
(PDC). For location of relay, refer to label on underside of PDC
cover. Start and run engine until it stalls. Attempt restarting engine
until it will no longer run.
3) Unplug connector from an injector. Attach one end of a
jumper wire (18 gauge or smaller) with alligator clips to either
injector terminal. Connect other end of jumper wire to positive side
of battery. Connect one end of a second jumper wire to remaining
injector terminal.
WARNING: Powering an injector for more than a few seconds will
permanently damage injector.
4) Touch other end of second jumper wire to negative terminal
of battery for no more than a few seconds. Place a rag below fuel
line. Disconnect quick-connect fitting at fuel rail. See FUEL LINE
DISCONNECT FITTINGS. Return fuel pump relay to PDC.
Compressed Natural Gas Fuel Tube Purging (5.2L)
1) Close control valve (clockwise) on all fuel cylinders.
Open manual shutoff valve (open when handle is parallel to fuel
tubes).
2) Start and operate engine until it runs out of fuel.
Attempt 3 more engine starts. If check valve or fuel fill receptacle

Fig. 2: Identifying Retainer Type Fuel Line Disconnect Fittings
Courtesy of Chrysler Corp.
ENGINE
Removal (Ram Van/Wagon)
1) Release fuel pressure. See FUEL PRESSURE RELEASE.
Disconnect negative battery cable. Drain cooling system and engine
oil. Remove and discard oil filter.
2) Remove engine cover, air cleaner and oil dipstick.
Discharge A/C system (if equipped) using approved refrigerant
recovery/recycling equipment. Disconnect A/C lines at condenser, and
plug openings. Remove A/C compressor. Disconnect fan shroud.
3) Remove front bumper, grille and support brace. Disconnect
coolant hoses. Remove radiator, condenser and support as an assembly.
4) Remove upper fan shroud. Remove power steering pump with
hoses attached, and set aside. Remove air pump, spark plug wires and
distributor cap. Disconnect necessary electrical wiring, coolant hoses
and vacuum hoses. Disconnect fuel lines. See FUEL LINE DISCONNECT

FITTINGS. Remove air cleaner, throttle body, drive belts, generator,
fan and fan pulley. Remove lower fan shroud.
CAUTION: When removing engine, DO NOT lift engine by intake manifold.
5) Remove intake manifold. See INTAKE MANIFOLD. Raise and
support vehicle. Remove starter. Remove exhaust pipe and heat shields.
Disconnect transmission shift linkage. Remove crank sensor.
6) On A/T models, remove transmission inspection cover. Mark
torque converter-to-flexplate position for installation reference.
Remove torque converter-to-flexplate bolts. On M/T models, disconnect
clutch release mechanism at clutch housing.
7) Attach engine hoist to cylinder heads (at intake manifold
flanges). On all models, support transmission using a floor jack.
Remove transmission or clutch housing-to-cylinder block bolts. Remove
engine mount bolts. Remove engine out front of vehicle.
Installation
To install, reverse removal procedure. Tighten bolts/nuts to
specification. See TORQUE SPECIFICATIONS table. On A/T models, ensure
reference marks on torque converter and flexplate are aligned.
Evacuate and charge A/C system.
Removal ( Dakota 2WD, Durango 2WD, Grand Cherokee & Ram
Pickup)
1) Release fuel pressure. See FUEL PRESSURE RELEASE.
Disconnect and remove battery. On all except Pickup, scribe hood
hinges for installation reference and remove hood.
2) On all models, drain cooling system. Disconnect coolant
hoses. Remove radiator, fan and shroud. Discharge A/C system (if
equipped) using approved refrigerant recovery/recycling equipment.
Disconnect A/C lines, and plug openings. On Pickup, remove upper core
support, transmission cooler and A/C condenser. On all models, remove
belt, air cleaner, vacuum lines, distributor cap and wiring.
3) Disconnect necessary electrical wiring. Disconnect fuel
lines. See FUEL LINE DISCONNECT FITTINGS. Remove throttle body and
linkage. Remove intake manifold. Remove starter, generator, charcoal
canister and horns. Disconnect power steering hoses (if equipped).
Raise and support vehicle. Drain oil. Disconnect exhaust pipe at
exhaust manifold.
4) On A/T models, remove transmission housing inspection
plate. Mark torque converter-to-flexplate position for installation
reference. Remove torque converter-to-flexplate bolts. Remove bracket
for transmission cooler lines.
NOTE: It may be necessary to remove manual transmission if
transmission cannot be supported using floor jack.
5) On M/T models, disconnect clutch release mechanism at
clutch housing. On all models, support transmission using a floor
jack. Remove transmission or clutch housing-to-cylinder block bolts.
Install engine lifting fixture, and attach chain.
CAUTION: When removing engine, DO NOT lift engine by intake manifold.
6) On Ram Pickup and Grand Cherokee, remove front engine
mount bolts. Remove engine from vehicle. On Dakota 2WD and Durango 2WD
models, remove front engine mount through-bolts. See Fig. 3. Remove
engine from vehicle.
Installation
To install, reverse removal procedure. Tighten bolts/nuts to
specification. See TORQUE SPECIFICATIONS table. On A/T models, ensure

reference marks on torque converter and flexplate are aligned.
Evacuate and charge A/C system.
Removal (Durango 4WD & Dakota 4WD)
1) Release fuel pressure. See FUEL PRESSURE RELEASE.
Disconnect and remove battery. Scribe hood hinges for installation
reference and remove hood.
2) Drain cooling system. Disconnect coolant hoses. Remove
radiator, fan and shroud. Discharge A/C system (if equipped) using
approved refrigerant recovery/recycling equipment. Disconnect A/C
lines, and plug openings. Remove air cleaner, vacuum lines,
distributor cap and wiring.
3) Disconnect necessary electrical wiring. Disconnect fuel
lines. See FUEL LINE DISCONNECT FITTINGS. Disconnect accelerator
linkage. Remove throttle body. Remove starter and generator.
Disconnect power steering hoses. Raise and support vehicle. Drain oil.
Disconnect exhaust pipe at exhaust manifold.
NOTE: Engine, transmission and front axle are connected and
supported with insulators and brackets. See Fig. 3.
4) On left side, remove 2 bolts attaching differential pinion
nose bracket-to-bellhousing bolts. Remove pinion nose bracket-to-
adapter bolts (located on top of differential, near pinion). Separate
engine from engine mount by removing engine mount through-bolt and nut
located on top of engine mount.
5) On right side, remove 2 axle-to-bracket bolts and bracket-
to-bellhousing bolt. Separate engine from engine mount by removing
engine mount through-bolt and nut located on top of engine mount.
Remove engine from vehicle.