Suzuki AN400 Service Manual page 72

1A-9 Engine General Information and Diagnosis:
Condition
Engine noisy (Noise
seems to come from
piston)
Engine noisy (Noise
seems to come from
timing chain)
Engine noisy (Noise
seems to come from
crankshaft)
Engine noisy (Noise
seems to come from
balancer)
Engine noisy (Noise
seems to come from
transmission)
Engine noisy (Noise
seems to come from
water pump)
Engine runs poorly in
high speed range
(Defective engine internal/
electrical parts)
Engine runs poorly in
high speed range
(Defective air flow
system)
Engine runs poorly in
high speed range
(Defective control circuit
or sensor)
Possible cause
Worn down piston or cylinder.
Combustion chambers fouled with
carbon.
Worn piston pin or piston pin bore.
Worn piston rings or ring grooves.
Stretched chain.
Worn sprockets.
Tension adjuster not working.
Rattling bearings due to wear.
Worn and burnt journal bearings.
Worn and burnt journal bearings.
Worn or rubbing gears.
Worn splines.
Worn or rubbing primary gears.
Worn bearings.
Worn or damaged impeller shaft.
Worn or damaged mechanical seal.
Contact between pump case and
impeller.
Weakened valve springs.
Worn camshafts.
Valve timing out of adjustment.
Too narrow spark plug gap.
Ignition not advanced sufficiently due to
poorly working timing advance circuit.
Defective ignition coil.
Defective CKP sensor.
Defective ECM.
Clogged air cleaner element.
Clogged fuel hose, resulting in
inadequate fuel supply to injector.
Defective fuel pump.
Defective TP sensor.
Defective STP sensor/STVA.
Clogged air cleaner element.
Defective throttle valves.
Defective ISC valve.
Sucking air from throttle body joint.
Defective ECM.
Low fuel pressure.
Defective TP sensor.
Defective IAT sensor.
Defective IAP sensor.
Defective AP sensor.
Defective ECM.
TP sensor out of adjustment.
Defective STP sensor/STVA.
Defective fuel tank pressure control
valve.
Correction / Reference Item
Replace.
Clean.
Replace.
Replace.
Replace.
Replace.
Repair or replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Adjust.
Adjust.
Replace ECM.
Replace.
Replace.
Replace.
Clean.
Clean and prime.
Replace.
Replace.
Replace.
Clean or replace.
Adjust or replace.
Replace.
Repair or replace.
Replace.
Repair or replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Adjust.
Replace.
Replace.