Isuzu 2000 Trooper Workshop Manual page 727

6A–14 ENGINE MECHANICAL
Abnormal Combustion
Condition
Trouble in fuel system
Trouble in emission control system
Trouble in ignition system
Possible cause
Fuel pressure control valve defective
Fuel filter clogged
Fuel pump clogged
Fuel tank or fuel pipe clogged
Fuel injector clogged
Fuel pump relay defective
Power supply cable for fuel pump
broken or poor connections
Mass Airflow (MAF) sensor circuit
open or defective
MAF Sensor defective
Manifold Absolute Pressure Sensor
circuit open or shorted
Manifold Absolute Pressure Sensor
defective
Engine Coolant Temperature (ECT)
Sensor circuit open or shorted
ECT Sensor defective
Throttle Position Sensor adjustment
incorrect
Throttle Position Sensor defective
Throttle Position Sensor connector
poor connections
Vehicle Speed Sensor cable poor
connections or defective
Vehicle Speed Sensor loosely fixed
Vehicle Speed Sensor in wrong
contact or defective
Powertrain Control Module cable
poor connections or defective
Heated Oxygen Sensor circuit open
Heated Oxygen Sensor defective
Signal vacuum hose loosely fitted or
defective
EGR Valve circuit open or shorted
Exhaust Gas Recirculation Valve
defective
ECT Sensor circuit open or shorted
Canister Purge Valve circuit open or
shorted
Canister Purge Valve defective
ECT Sensor defective
Positive Crankcase
(PCV) valve and hose clogged
Evaporator system
————
Replace
Replace
Clean or replace
Clean or replace
Clean or replace
Replace
Reconnect, correct or replace
Correct or replace
Replace
Correct or replace
Replace
Correct or replace
Replace
Readjust
Replace
Reconnect
Correct or replace
Fix tightly
Replace
Correct or replace
Correct or replace
Replace
Correct or replace
Correct or replace
Replace
Correct or replace
Correct or replace
Replace
Replace
Ventilation Correct or replace
Refer to Section 6E
Refer to "Engine Lacks Power"
Correction