exj 9a, JEEP Manuals, Electronic Service Manual (jeep cherokee xj do 2000)
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XJ
ENGINE
9 - 1
ENGINE
TABLE OF CONTENTS
page
page
DESCRIPTION AND OPERATION
DIAGNOSIS AND TESTING
SERVICE DIAGNOSIS—DIESEL—
SERVICE DIAGNOSIS—DIESEL—
SERVICE PROCEDURES
REMOVAL AND INSTALLATION
OIL FILTER ADAPTER AND ENGINE OIL
PISTONS AND CONNECTING ROD
DISASSEMBLY AND ASSEMBLY
CLEANING AND INSPECTION
PISTONS AND CONNECTING ROD
SPECIFICATIONS
SPECIAL TOOLS
DESCRIPTION AND OPERATION
ENGINE IDENTIFICATION
DESCRIPTION
The engine model code and serial number are
stamped on the left side of the engine block, just
below the oil dipstick tube (Fig. 1). The engine code
on the XJ 2.5L is DD85C followed by a 5 digit serial
number.
Fig. 1 Engine Code Location
 9 - 2
ENGINE
XJ
DIAGNOSIS AND TESTING (Continued)
Displacement ........2.5L (2499 cc)
Bore ...............92.00
Stroke ..............94.00
Compression Ratio ....21:1
Vacuum at idle .......600mm/Hg (23.6 In/Hg)
Belt Tension .........400/500 N Automatic
Tensioner
Thermostat Opening . . . 80°C
2°C
Generator Rating .....Denso 12V—95A
Cooling System Capacity. 9.5 Liter
P/S Capacity .........0.75 Liter
Engine Oil Capacity . . . 7.2L w/filter change
Timing System .......Pushrod operated overhead
valves, with gear-driven
camshaft in crankcase.
Air Intake ...........Dryfilter.
Fuel Feed ...........Vanepump incorporated in
injection pump.
Fuel System .........Indirect fuel injection
(precumbustion chamber).
Combustion Cycle .....4stroke
Cooling System .......Water cooling.
Injection Pump .......Rotary pump and
electronically managed.
Lubrication ..........Pressure lubrication by
rotary pump, full-flow
filtration.
Engine Rotation .......Clockwise viewed from
front cover.
6
Engine Description
DIAGNOSIS AND TESTING
SERVICE DIAGNOSIS—DIESEL—
PERFORMANCE
CONDITION
POSSIBLE CAUSES
CORRECTION
ENGINE WILL NOT CRANK
OR CRANKS SLOWLY
1. Starting motor operating, but not
cranking the engine.
1. Remove the starter motor. Check for
broken flywheel teeth or a broken
starting motor spring.
2. Crankshaft rotation restricted.
2. Rotate the engine to check for
rotational resistance.
3. Starting circuit connections loose or
corroded.
3. Clean and tighten connections.
4. Neutral safety switch or starter relay
inoperative.
4. Check starter relay supply voltage
and proper operation of neutral safety
switch (if equipped). Replace defective
parts.
5. Battery charge low.
5. Check battery voltage. Replace
battery if a charge cannot be held.
 XJ
ENGINE
9 - 3
DIAGNOSIS AND TESTING (Continued)
CONDITION
POSSIBLE CAUSES
CORRECTION
6. No voltage to starter solenoid.
6. Check voltage to solenoid. If
necessary, replace the solenoid.
7. Solenoid or starter motor
inoperative.
7. Replace starter motor.
ENGINE CRANKS, BUT WILL
NOT START NO SMOKE
1. No fuel in supply tank.
1. Fill fuel supply.
2. Electrical fuel shutdown solenoid not
operating.
2. Check for loose wires and verify that
the fuel shutdown solenoid and fuel
shutdown solenoid relay is functioning.
3. Exhaust plugged.
3. Remove the obstruction.
4. Fuel filter plugged.
4. Drain fuel/water separator and
replace fuel filter.
5. Excessive fuel inlet restriction.
5. Check fuel inlet restriction. Correct
cause.
6. Injection pump not getting fuel or
fuel is aerated.
6. Check fuel flow/bleed fuel system.
7. Worn or inoperative injection pump.
7. Visually check delivery with
externally connected injector to one of
the pump outlets. Repair or replace the
pump if fuel is not being delivered.
ENGINE HARD TO START,
OR WILL NOT START
SMOKE FROM EXHAUST
1. Incorrect starting procedure.
1. The fuel shutoff solenoid control
must be in the run position. Ensure
proper procedure is being used.
2. Cranking speed too slow.
2. (A) Verify that the transmission is not
engaged.
(B) Check the battery, starting motor
and look for loose or corroded wiring
connections.
3. Cylinder heads heater plugs relay
defective.
3. Verify system is working. Repair/
replace inoperative parts.
4. One or more cylinder head heater
plugs defective.
4. Verify system is working. Repair/
replace inoperative parts.
5. Insufficient intake air.
5. Inspect or replace filter and check
for obstruction to the air supply tube.
9 - 4
ENGINE
XJ
DIAGNOSIS AND TESTING (Continued)
CONDITION
POSSIBLE CAUSES
CORRECTION
ENGINE HARD TO START,
OR WILL NOT START
SMOKE FROM EXHAUST
(CONT.)
6. Air in fuel system or the fuel supply
is inadequate.
6. Check the flow through the filter and
bleed the system. Locate and eliminate
the air source.
7. Contaminated fuel.
7. Verify by operating the engine with
clean fuel from a temporary tank.
Check for presence of gasoline. Drain
and flush fuel supply tank. Replace
fuel/water separator filter.
8. Fuel screen plugged.
8. Check fuel screen.
9. One or more injectors worn or not
operating properly.
9. Check/replace improperly operating
injectors.
10. Worn or inoperative injection
pump.
10. Visually check fuel delivery with an
externally connected injector to one of
the pump outlets. Repair or replace the
pump if fuel is not being delivered.
11. Injection pump out of time.
11. Check/Time the pump (refer to
Group 14, Fuel System).
12. Engine compression low.
12. Check compression to identify the
problem.
13. Camshaft out of time.
13. Check camshaft timing.
ENGINE STARTS, BUT WILL
NOT KEEP RUNNING
1. Cylinder heads heater plugs relay
defective.
1. Verify system is working. Repair/
replace inoperative parts.
2. One or more cylinder head heater
plugs defective.
2. Verify system is working. Repair/
replace inoperative parts.
3. Intake air or exhaust system
restricted.
3. Visually check for exhaust restriction
and inspect the air intake.
4. Air in the fuel supply system or the
fuel supply is inadequate.
4. Check flow through the filter and
bleed the system. Locate and eliminate
the air source.
5. Fuel waxing due to extremely cold
weather.
5. Verify by inspecting the fuel filter.
Clean the system and use climatized
fuel. Replace fuel/water separator filter.
Check fuel heater for proper operation.
6. Contaminated fuel.
6. Verify by operating the engine with
clean fuel from a temporary supply
tank. Check for presence of gasoline.
Replace fuel/water separator filter.
SURGING (SPEED
CHANGE)
1. If the condition occurs at idle, the
idle speed is set too low for the
accessories.
1. Adjust the idle speed.
2. High pressure fuel leak.
2. Inspect/correct leaks in the high
pressure lines. Fitting and delivery
valve sealing washers.
3. One or more injectors worn or not
operating properly.
3. Check/replace the inoperative
injectors.
4. Improperly operating injection pump.
4. Replace the injector pump.
XJ
ENGINE
9 - 5
DIAGNOSIS AND TESTING (Continued)
CONDITION
POSSIBLE CAUSES
CORRECTION
ROUGH IDLE
(IRREGULARLY FIRING OR
ENGINE SHAKING)
1. If engine is cold, glow plug relay on
glow plug(s) defective.
1. Refer to troubleshooting for cylinder
head heater plugs (see Group 14, Fuel
system).
2. Engine mounts damaged or loose.
2. Repair or replace mounts.
3. High pressure fuel leaks.
3. Correct leaks in the high pressure
lines, fittings or delivery valves.
4. Air in the fuel system.
4. Bleed the fuel system and eliminate
the source of the air.
5. Sticking needle valve in an injector.
5. Check and replace the injector with
the sticking needle valve.
ENGINE RUNS ROUGH
1. Fuel injection lines leaking.
1. Correct leaks in the high pressure
lines, fittings, injectors sealing washers
or delivery valves.
2. Air in the fuel or the fuel supply is
inadequate.
2. Check the flow through the filter and
bleed the system. Locate and eliminate
the air source.
3. Contaminated fuel.
3. Verify by operating the engine with
clean fuel from a temporary supply
tank. Check for presence of gasoline.
Replace fuel/water separator filter.
4. Incorrect valve operation.
4. Check for a bent push rod and
adjust valves. Replace push rod, if
necessary.
5. Injection pump timing incorrect.
5. Check/time pump (refer to Group 14,
Fuel System).
6. Improperly operating injectors.
6. Replace inoperative injectors.
7. Defective injection pump (delivery
valve).
7. Repair or replace injection pump.
8. Camshaft out of time.
8. Check/correct gear train timing
alignment.
9. Damaged camshaft or tappets.
9. Inspect camshaft valve lift. Replace
camshaft and tappets.
10. Automatic timing advance not
operating.
10. Check injection pump. Check fuel
injector sensor at number 1 cylinder
injector.
ENGINE RPM WILL NOT
REACH RATED SPEED
1. Engine overload.
1. Verify high idle speed without load.
Investigate operation to be sure correct
gear is being used.
2. Improperly operating tachometer.
2. Verify engine speed with hand
tachometer, correct as required.
3. Inadequate fuel supply.
3. Check the fuel flow through the
system to locate the reason for
inadequate fuel supply, correct as
required.
4. Air/fuel controls leak.
4. Check and repair leak. Check AFC
tubing for obstruction.
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