Suzuki VZ800 Service Manual page 394

10-6 SERVICING INFORMATION
Complaint
Engine idles poorly.
Engine stalls easily. Incorrect fuel/air mixture
Symptom and possible causes
1. Out of adjustment valve clearance
2. Poor seating of valves
3. Defective valve guides
4. Worn down camshafts
5. Too wide spark plug gaps
6. Defective ignition coil
7. Defective CKP sensor
8. Defective ECM
9. Defective TP sensor
10. Defective fuel pump
11. Imbalanced throttle valve
12. Damaged or cracked vacuum hose
1. Defective IAP sensor or circuit
2. Clogged fuel filter
3. Defective fuel pump
4. Defective fuel pressure regulator
5. Defective ECT sensor
6. Defective thermostat
7. Defective IAT sensor
8. Damaged or cracked vacuum hose
Improperly working fuel injector
1. Defective fuel injector
2. No injection signal from ECM
3. Open or short circuited wiring connection
4. Defective battery or low battery voltage
Improperly working control circuit or sensors
1. Defective ECM
2. Defective fuel pressure regulator
3. Defective TP sensor
4. Defective IAT sensor
5. Defective CKP sensor
6. Defective ECT sensor
7. Defective fuel pump relay
Improperly working engine internal parts
1. Fouled spark plugs
2. Defective CKP sensor or ECM
3. Clogged fuel hose
4. Out of adjustment valve clearance
Remedy
Adjust.
Replace or repair.
Replace.
Replace.
Adjust or replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Adjust.
Replace.
Repair or replace.
Clean or replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Repair or replace.
Repair or replace.
Replace or recharge.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Clean.
Replace.
Clean.
Adjust.