Fig. 2: 4.0L Fuel Pump, Filter & Accumulator
Courtesy of Chrysler Motors
TESTING & DIAGNOSIS
FUEL PUMP PRESSURE TEST
2.5L TBI
1) Adjustment of fuel pressure is required after replacement
of pressure regulator. Remove air inlet from throttle body. Connect
tachometer to diagnostic connector terminals D1-1 and D1-3. Connect
fuel pressure gauge to fuel body pressure test fitting.
NOTE: Some TBI models do not have a pressure test fitting on
throttle body. Use Fitting (PN 8983 501 572) for this
purpose.
2) Start engine and accelerate to 2000 RPM. Turn adjustment
screw to obtain 14.5 psi (1.02 kg/cm
) fuel pressure. Location of
adjustment screw is on bottom of regulator. Install lead seal ball to
cover regulator adjustment screw after adjusting fuel pressure to
specification. Turn ignition off. Disconnect fuel pressure gauge.
Install cap on test fitting. Install air inlet.
NOTE: To increase fuel pressure, turn adjustment screw inward. To
decrease fuel pressure, turn adjustment screw outward.
4.0L MPFI
1) Remove cap from pressure test port in fuel rail. Connect
Fuel Pressure Gauge (J-37730-1) to pressure fitting. Start vehicle.
Pressure should be approximately 31 psi (2.7 kg/cm
) with vacuum
hose connected to pressure regulator.
2) Pressure should be 39 psi (2.74 kg/cm
) with vacuum
hose removed from regulator. If fuel pressure is not to
specifications, check for kinks or restricting bends in fuel supply
and return lines. Check fuel pump flow rate. Pump should deliver
minimum of 1.06 quarts (one liter) of fuel per minute with fuel
return line pinched off.
3) If flow is inadequate, check system for plugged fuel
filter or filter sock. Fuel pump flow rate can be checked by
connecting a hose to fuel test port on fuel rail and inserting other
end in clean container.
4) To operate fuel pump, install a jumper wire into
diagnostic connector terminals D1-5 and D1-6. Pinch off fuel return
line to ensure that no fuel returns to fuel tank. If fuel pressure is
still not to specifications and fuel flow is normal, replace
regulator.
REMOVAL & INSTALLATION
FUEL PUMP
Removal (2.5L TBI)
1) Disconnect battery cables. Ensure fuel level is less than
1/2 for this procedure. Remove fuel outlet and return hoses. Remove
sending unit wires. Remove sending unit retaining lock ring.
2) Remove sending unit/pump assembly with "O" ring seal.
Disconnect fuel hose from fuel pump. Disconnect wires from fuel pump.
Remove fuel pump from sending unit.
Installation
Clean seal contact are of fuel tank. Install new "O" ring
seal. Install a new filter on end of suction tube. Position sending
unit/pump assembly in tank. To complete installation, reverse removal
procedure. Start engine and check for leaks.
CAUTION: Fuel leaks can develop from over tightening sending
unit/pump during installation.
Removal (4.0L MPFI)
Install clamps (MOT. 453.01) on fuel pump inlet and outlet
hoses. Disconnect hoses from fuel pump. Disconnect electrical
connectors. Remove retaining strap. Remove fuel pump.
Installation
To install, reverse removal procedure. Ensure that clamps
(MOT. 453.01) have been removed from fuel lines. Start engine and
check for leaks.
NOTE: Accumulator is located between fuel pump and fuel filter on
4.0L models.
the ENGINE PERFORMANCE section.
Fuel filter should be drained whenever "WATER IN FUEL"
warning light glows. Diesel fuel can damage asphalt and
painted surfaces. Always place a drain pan under fuel filter
to collect contaminated fuel. See Fig. 2.
1) Stop vehicle and turn engine off. Attach a long piece
of tubing to drain cock outlet. Place end of drain hose into
drain pan. Open filter assembly vent valve (Black + shaped
knob) and drain cock.
2) Drain approximately 1/2 pint (.24 Liters) from fuel
filter. Close vent valve and drain cock. Start engine and
check for leaks. If "WATER IN FUEL" warning lamp comes on
again, remove water contaminated fuel from fuel lines and
fuel tank.
WARNING: DO NOT bleed fuel lines on hot engine, as high exhaust
temperatures could cause fire. Use care when bleeding fuel
lines, as fuel is under extreme pressure and could penetrate
skin, causing personal injury. Wear safety goggles and
protective clothing when bleeding fuel lines.
CAUTION: DO NOT drain fuel/water separator when engine is running or
hot. Allow engine to cool before draining. Verify that the
WATER IN FUEL light on instrument panel is OFF.
Fig. 3: Locking Crankshaft at TDC
Courtesy of American Motors/Jeep Corp.
Brake Caliper Bushings ....... GE 661 or DOW 111 Silicone Grease
Caliper Slide Pins .......... GE 661 or DOW 111 Silicone Grease
Wheel Bearings ............ Multi-Purpose NLGI Grade 2EP, GC-LB
Drive Shaft U-Joints ...... Multi-Purpose NLGI Grade 2EP, GC-LB
Steering Linkage (4)( 5) ... Multi-Purpose NLGI Grade 2EP, GC-LB
Ball Joints ( 4)( 6) ........ Multi-Purpose NLGI Grade 2EP, GC-LB
Engine Oil Filter (Diesel) ( 7) .... AMC/Jeep (P/N 8983 002 656)
Weatherstrip ......................... Silicone Spray Lubricant
( 1) - SAE 10W-30 SH/CD is preferred.
( 2) - Add 2 Ozs. (59 ml) of Limited-Slip differential lubricant
additive when changing fluid.
( 3) - For vehicles operating under heavy-duty towing conditions,
use SAE 75W-140 Synthetic lube.
NOTE: Before using SAE 75W-140 Synthetic the old fluid must be
DRAINED and FLUSHED with clean mineral based (non-synthetic)
axle lubricant. Then refill with new synthetic lube.
( 4) - Use low pressure grease gun to prevent seal damage.
( 5) - Fill until lubricant squeezes out from the base of seals.
( 6) - Fill ball joint until seal starts to swell.
( 7) - Use of AMC/Jeep Oil Filter is RECOMMENDED.
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FLUID CAPACITIES
FLUID CAPACITIES TABLE\
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Application Quantity ( 1)
A/C System R-12 Refrigerant Capacity ............... 36-40 Ozs.
Automatic Transmission
1984-86 (904 HD)
Fluid Change .............................. 4.0 Qts. (3.8L)
Overhaul (Dry Fill) ....................... 8.0 Qts. (7.6L)
1987-88
Fluid Change .............................. 4.0 Qts. (3.8L)
Overhaul (Dry Fill) ....................... 8.5 Qts. (8.0L)
Cooling System ( 2)
4-Cylinder ................................. 10.0 Qts. (9.5L)
6-Cylinder ................................ 12.0 Qts. (11.4L)
4-Cylinder Turbo Diesel (1985-87) ........... 9.0 Qts. (8.5L)
Engine Oil
4-Cylinder .................................. 4.0 Qts. (3.8L)
6-Cylinder .................................. 6.0 Qts. (5.7L)
4-Cylinder Turbo Diesel (1985-87) ........... 5.5 Qts. (8.5L)
Fuel Tank
Standard ................................. 13.5 Gals. (51.1L)
Optional ................................... 20 Gals. (75.7L)
Manual Transmission ( 3)
AX4 (AISIN) ................................. 7.4 Pts. (3.5L)
T4 (Borg-Warner) ............................ 3.9 Pts. (1.8L)
AX5 (AISIN) ................................. 7.0 Pts. (3.3L)
T5 (Borg-Warner) ............................ 4.5 Pts. (2.1L)
Transfer Case
1985-86
Selec-Trac (229 Full-Time) ................ 6.0 Pts. (2.8L)
Command-Trac (Part-Time 207) .............. 4.5 Pts. (2.1L)
1987
Selec-Trac ................................ 2.5 Pts. (1.2L)
Command-Trac .............................. 2.2 Pts. (1.0L)
1988
Selec-Trac ................................ 3.0 Pts. (1.4L)
ELECTROSTATIC DISCHARGE SENSITIVE (ESD) PARTS
WARNING: Many solid state electrical components can be damaged by
static electricity (ESD). Some will display a warning label,
but many will not. Discharge personal static electricity by
touching a metal ground point on the vehicle prior to
servicing any ESD sensitive component.
ENGINE OIL
CAUTION: Never use non-detergent or straight mineral oil.
CAUTION: Do not use reclaimed fluid, mineral oil, fluid that was
stored in old or open containers, or fluid inferior to AMC
Standard AM 4101. Be sure to handle the fluid in clean
containers that will not introduce even a slight amount of
foreign liquids or particles. Such contamination of fluid
could lead to hydraulic system failure.
ENGINE OIL FILTER (GASOLINE)
CAUTION: Verify that proper Oil Filter is being used. Filters with
metric threads (M20 x 1.5) must be used with some engines.
Other engines use SAE type (3/4" x 16) threads, and must
use an oil filter with these threads. Possible engine damage
can occur with improper oil filter.
ENGINE OIL FILTER (TURBO DIESEL ONLY)
CAUTION: The engine oil filter has METRIC threads. Use of a filter
with improper threads can result in oil leakage and
possible engine damage. Look for thread size symbol M20x1.5
on filter.
FUEL SYSTEM SERVICE
WARNING: DO NOT bleed fuel lines on hot engine, as high exhaust
temperatures could cause fire. Use care when bleeding fuel
lines, as fuel is under extreme pressure and could penetrate
skin, causing personal injury. Wear safety goggles and
protective clothing when bleeding fuel lines.
WARNING: Relieve fuel system pressure prior to servicing any fuel
system component.
HALOGEN BULBS
Halogen bulbs contain pressurized gas which may explode if
overheated. DO NOT touch glass portion of bulb with bare hands. Eye
protection should be worn when handling or working around halogen
bulbs.
RADIATOR CAP
CAUTION: Always disconnect the fan motor when working near the
radiator fan. The fan is temperature controlled and could
start at any time even when the ignition key is in the OFF
position. DO NOT loosen or remove radiator cap when cooling
system is hot.
STARTING FLUID USE (TURBO DIESEL)
PVC & C RAN KCASE V EN TIL A TIO N S YSTE M
1988 J e ep C hero ke e
1987-89 Crankcase Ventilation
PCV AND CCV SYSTEMS
Jeep
DESCRIPTION
Crankcase ventilation systems are designed to prevent
contaminating hydrocarbons from escaping to the atmosphere. This is
accomplished by routing vapors from the crankcase through a
vacuum-controlled ventilating valve (PCV Valve) into the intake
manifold. In the intake manifold, the crankcase vapors mix with the
air/fuel mixture and are burned in the combustion process. PCV systems
are used on all 4.2L and 5.9L engines. 2.5L and 4.0L engines do not
employ PCV systems, instead they are equipped with a Crankcase
Ventilation System (CCV). The CCV system performs the same function as\
a conventional PCV system, but does not use a vacuum controlled valve.
OPERATION
PCV SYSTEM
Air is supplied to the crankcase ventilation system through
a crankcase ventilating filter assembly, located in air cleaner
housing or on rocker arm cover.
When engine is operating, fresh air enters crankcase
ventilation system through the air cleaner and filter.
Air then flows into the rocker arm cover and valve
compartment. It combines with blow-by gas and unburned air/fuel
mixture and burns in combustion chamber. See Fig. 1.
Fig. 1: Typical Crankcase Ventilation System
Ventilator valve is held closed by spring pressure when
engine is not running. See Fig. 2. This prevents accumulation of
hydrocarbon fumes from collecting in intake manifold, which could