Isuzu 20LE - Rough Engine Idling or Engine Stalling

6-4 ENGINE DIAGNOSIS (C22NE, 22LE, 20LE)
Rough Engine Idling or Engine Stalling
Condition Possible cause Correction
Trouble in fuel injection system Idle air control valve defective Replace
Throttle shutting off incomplete Correct or replace
Throttle position sensor circuit
open or shorted
Correct or replace
Fuel injector circuits open or
shorted
Correct or replace
Fuel injectors damaged Replace
Fuel pump relay defective Replace
Manifold Absolute Pressure
Sensor cable disconnected or
broken
Correct or replace
Manifold Absolute Pressure
Sensor defective
Replace
Engine Coolant Temperature
Sensor cable disconnected or
broken
Correct or replace
Engine Coolant Temperature
Sensor defective
Replace
Intake Air Temperature sensor
cable disconnected or broken
Correct or replace
Intake Air Temperature sensor
defective
Replace
Knock Sensor (KS) circuits open
or shorted
Correct or replace
KS defective Replace
KS Module circuits open or ground Correct or replace
KS Module defective Replace
Vehicle Speed Sensor circuit open
or shorted
Correct or replace
Vehicle Speed Sensor defective Replace
Trouble in emission control
system
Engine Control Module defective Replace
Canister purge solenoid circuit
open
Correct
Canister purge solenoid defective Replace
Evaporative Emission Canister
Purge control valve defective
Replace
Trouble in ignition system Refer to Hard Start
Troubleshooting Guide
Others Engine lacks compression Refer to Hard Start
Troubleshooting Guide
Valve incorrectly seated Lap valve
Air Cleaner Filter clogged Replace filter element
Valve timing incorrect Readjust
Idle air control valve broken Replace