Jeep Cherokee 2000 Service Manual - page 699
SERVICE DIAGNOSIS—PERFORMANCE
ENGINE PERFORMANCE DIAGNOSIS CHART
CONDITION
POSSIBLE CAUSES
CORRECTION
ENGINE WILL NOT CRANK
1. Weak or dead battery
1. Charge/Replace Battery. Refer to
Group 8A, Battery, for correct
procedures. Check charging system.
Refer to Group 8C, Charging
Systems, for correct procedures.
2. Corroded or loose battery
connections
2. Clean/tighten suspect battery/
starter connections
3. Faulty starter or related circuit(s)
3. Check starting system. Refer to
Group 8B, Starting Systems, for
correct diagnostics/procedures
4. Siezed accessory drive
component
4. Remove accessory drive belt and
attempt to start engine. If engine
starts, repair/replace siezed
component.
5. Engine internal mechanical
failure or hydro-static lock
5. Refer to Group 9, Engine, for
correct diagnostics/procedures
ENGINE CRANKS BUT WILL NOT
START
1. No spark
1. Check for spark. Refer to Group
8D, Ignition System, for correct
procedures.
2. No fuel
2. Perform fuel pressure test, and if
necessary, inspect fuel injector(s)
and driver circuits. Refer to Group
14, Fuel System, for correct
procedures.
3. Low or no engine compression
3. Perform cylinder compression
pressure test. Refer to Group 9,
Engine, for correct procedures.
ENGINE LOSS OF POWER
1. Worn or burned distributor rotor
1. Install new distributor rotor
2. Worn distributor shaft
2. Remove and repair distributor
(Refer to group 8D, Ignition System
3. Worn or incorrect gapped spark
plugs
3. Clean plugs and set gap. (Refer
to group 8D, Ignition System)
4. Dirt or water in fuel system
4. Clean system and replace fuel
filter
5. Faulty fuel pump
5. Install new fuel pump
6. Incorrect valve timing
6. Correct valve timing
7. Blown cylinder head gasket
7. Install new cylinder head gasket
8. Low compression
8. Test cylinder compression
9. Burned, warped, or pitted valves
9. Install/Reface valves as
necessary
10. Plugged or restricted exhaust
system
10. Install new parts as necessary
11. Faulty ignition cables
11. Replace any cracked or shorted
cables
XJ
2.5L ENGINE
9 - 9
DIAGNOSIS AND TESTING (Continued)