Diagnostic Information And Procedures; Engine Symptom Diagnosis - Suzuki GSF650A Service Manual

1A-9 Engine General Information and Diagnosis:

Engine Symptom Diagnosis

Condition
Engine will not start or is
hard to start
(Compression too low)
Engine will not start or is
hard to start (Plugs not
sparking)
Engine will not start or is
hard to start (No fuel
reaching the intake
manifold)
Engine will not start or is
hard to start (Incorrect
fuel/air mixture)
Engine idles poorly
Engine stalls often
(Incorrect fuel/air mixture)

Diagnostic Information and Procedures

Possible cause
Valve clearance out of adjustment.
Worn valve guides or poor seating of
valves.
Mistimed valves.
Excessively worn piston rings.
Worn-down cylinder bores.
Starter motor cranks too slowly.
Poor seating of spark plugs.
Fouled spark plugs.
Wet spark plugs.
Defective ignition coil/plug cap.
Defective CKP sensor.
Defective ECM.
Open-circuited wiring connections.
Clogged fuel filter or fuel hose.
Defective fuel pump.
Defective fuel pressure regulator.
Defective fuel injectors.
Defective fuel pump relay.
Defective ECM.
Open-circuited wiring connections.
Defective fuel pump.
Defective fuel pressure regulator.
Defective TP sensor.
Defective CKP sensor.
Defective IAP sensor.
Defective ECM.
Defective ECT sensor.
Defective IAT sensors.
Valve clearance out of adjustment.
Poor seating of valves.
Defective valve guides.
Worn down camshafts.
Too wide spark plug gaps.
Defective ignition coil/plug gap.
Defective CKP.
Defective ECM.
Defective TP sensor.
Defective fuel pump.
Defective ISC valve.
Imbalanced throttle valve.
Damaged or cranked vacuum hose.
Defective IAP sensor or circuit.
Clogged fuel filter.
Defective fuel pump.
Defective fuel pressure regulator.
Damaged or cracked vacuum hose.
Defective ECT sensor.
Defective thermostat.
Defective IAT sensors.
Correction / Reference Item
Adjust.
Repair or replace.
Adjust.
Replace.
Replace.
Refer to "Starting System Diagram in Section
1I (Page 1I-1)".
Retighten.
Clean.
Clean and dry.
Replace.
Replace.
Replace.
Repair or replace.
Clean or replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Check and repair.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Adjust.
Replace or repair.
Replace.
Replace.
Adjust or replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Adjust.
Replace.
Repair or replace.
Clean or replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
B817H21104001