Diagnostic Information And Procedures; Engine Symptom Diagnosis - Suzuki GSF1250 Service Manual

1A-7 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

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.
Blown cylinder head gasket.
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.
Dirty throttle body.
Defective ISC valve.
Valve clearance out of adjustment.
Poor seating of valves.
Defective valve guides.
Worn down camshafts.
Too wide spark plug gaps.
Defective ignition coil/plug caps.
Defective CKP sensor.
Defective ECM.
Defective TP sensor.
Defective fuel pump.
Imbalanced throttle valve.
Dirty throttle body.
Damaged or cranked vacuum hose.
Sucking air from intake pipe joint.
Damaged or clogged ISC valve.
ISC bad leaning.
Correction / Reference Item
Adjust.
Repair or replace.
Adjust.
Replace.
Replace.
Refer to "Starting System Diagram in Section
1I (Page 1I-1)".
Retighten.
Replace.
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.
Clean.
Replace.
Adjust.
Replace or repair.
Replace.
Replace.
Adjust or replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Adjust.
Clean.
Replace.
Repair or replace.
Repair or replace.
Reset learned value.
B718H11104001