6-22
ENGINE DIAGNOSIS (RHZ ENGINE WITH SINGLE-CONNECTOR ECM)
Condition
Possible Cause
Reference Item
Abnormal knocking
Fuel system out of order.
D
Fuel injection pipe
– Cracks
– Fuel leakage from joints
D
Faulty fuel injector
– Incorrect valve opening pressure
– Seized needle valve
– Improperly installed nozzle holder
– Faulty nozzle gasket
Engine and emission control system
out of order.
D
Faulty ECM
D
Faulty fuel injection pump
– Faulty fuel pressure regulator
– Faulty timer control valve
D
Faulty fuel temp. sensor
D
Faulty ECT sensor
Other
D
Faulty EGR valve
Replace.
Repair.
Inspect and replace.
Adjust.
Replace.
Repair.
Replace.
Replace.
Inspect and replace.
Inspect and replace.
Inspect and replace.
Inspect and replace.
Inspect and replace.
Inspect and replace.
Engine hesitates
when accelerating
Intake system out of order.
D
Clogged air cleaner element
D
Faulty turbocharger.
Fuel system out of order.
D
Fuel filter
– Dirty or clogged
– Water mixed in
D
Dirty or clogged fuel hose or pipe
D
Fuel injection pipe
– Cracks
– Fuel leakage from joints
D
Clogged fuel injector
Engine overheating.
Engine and emission control system
out of order.
D
Faulty ECM
D
Faulty fuel injection pump
– Faulty fuel pressure regulator
– Air mixed in
– Pump internal damage
– Faulty injection pump solenoid valve
–
(3rd piston deactivator)
– Faulty MAF sensor
D
Faulty TP sensor
(Accelerator stroke sensor)
D
Faulty intake air pressure sensor
D
Faulty CKP sensor
D
Faulty ECT sensor
D
Faulty IAT sensor
EGR system out of order.
D
Faulty EGR solenoid valve
D
Faulty EGR valve
Low compression.
Other
D
Mal-adjusted accelerator cable
Clean or replace.
Replace.
Replace.
Repair.
Clean or replace.
Replace.
Repair.
Inspect and replace.
Refer to “Overheating” section.
Inspect and replace.
Adjust.
Refill fuel in fuel tank.
Inspect and replace.
Inspect and replace.
Inspect and replace.
Inspect and replace.
Inspect and replace.
Inspect and replace.
Inspect and replace.
Inspect and replace.
Inspect and repair or replace EGR
system.
Inspect and repair or replace EGR
system.
Previously outlined.
Replace.