Suzuki Intruder VZR1800 Service Manual page 478

11-8 SERVICING INFORMATION
Complaint
Engine idles poorly.
Engine stalls often.
Symptom and possible causes
1. Tappet clearance out of adjustment
2. Poor seating of valves
3. Defective valve guides
4. Worn down camshafts
5. Too wide spark plug gaps
6. Defective ignition coils
7. Defective ignition coil/plug caps
8. Defective CKP sensor
9. Defective ECM
10. Defective TP sensor
11. Defective ISC valve
12. Defective fuel pump
13. Imbalanced throttle valve
14. Damaged or cracked vacuum hose
Incorrect fuel/air mixture
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
Fuel injector improperly operating
1. Defective fuel injectors
2. No injection signal from ECM
3. Open or short circuited wiring connection
4. Defective battery or low battery voltage
Control circuit or sensor improperly operating
1. Defective ECM
2. Defective fuel pressure regulator
3. Defective TP sensor
4. Defective IAT sensor
5. Defective ISC valve
6. Defective CKP sensor
7. Defective ECT sensor
8. Defective fuel pump relay
Engine internal parts improperly operating
1. Fouled spark plugs
2. Defective CKP sensor or ECM
3. Clogged fuel hose
4. Out of adjustment tappet clearance
Remedy
Adjust.
Replace or repair.
Replace.
Replace.
Adjust or replace.
Replace.
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.
Replace.
Clean.
Replace.
Clean.
Adjust.