Suzuki AN400 Service Manual page 73

Condition
Engine lacks power
(Defective engine internal/
electrical parts)
Engine lacks power
(Defective control circuit
or sensor)
Engine overheats
(Defective engine internal
parts)
Engine overheats (Lean
fuel/air mixture)
Engine overheats (The
other factors)
Dirty or heavy exhaust
smoke
Possible cause
Loss of valve clearance.
Weakened valve springs.
Valve timing out of adjustment.
Worn piston rings or cylinder.
Poor seating of valves.
Fouled spark plug.
Incorrect spark plug.
Clogged injector.
TP sensor out of adjustment.
Clogged air cleaner element.
Sucking air from throttle valve.
Too much engine oil.
Defective fuel pump or ECM.
Defective CKP sensor and ignition coil. Replace.
Low fuel pressure.
Defective TP sensor.
Defective IAT sensor.
Defective CKP sensor.
Defective IAP sensor.
Defective AP sensor.
Defective ECM.
TP sensor out of adjustment.
Defective STP sensor/STVA.
Defective fuel tank pressure control
valve.
Heavy carbon deposit on piston crown. Clean.
Not enough oil in the engine.
Defective oil pump or clogged oil circuit. Replace or clean.
Use of incorrect engine oil.
Sucking air from intake pipe.
Defective cooling system.
Short-circuited IAP sensor/lead wire.
Short-circuited IAT sensor/lead wire.
Sucking air from intake pipe joint.
Defective fuel injector.
Defective ECT sensor.
Ignition timing too advanced due to
defective timing advance system (ECT
sensor, CKP sensor and ECM.)
Worn piston rings or cylinder.
Too much engine oil in the engine.
Worn valve guides.
Scored or scuffed cylinder wall.
Worn valves stems.
Defective stem seals.
Worn oil ring side rails.
Engine General Information and Diagnosis:
Correction / Reference Item
Adjust.
Replace.
Adjust.
Replace.
Repair.
Clean or replace.
Adjust or replace.
Clean.
Adjust.
Clean.
Replace.
Drain out excess oil.
Replace.
Repair or replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Adjust.
Replace.
Replace.
Add oil.
Change.
Retighten or replace.
Refer to "Engine Cooling System Warning in
Section 1F (Page1F-1)".
Repair or replace.
Repair or replace.
Repair or replace.
Replace.
Replace.
Replace.
Replace.
Check and drain excess oil.
Replace.
Replace.
Replace.
Replace.
Replace.
1A-10