Suzuki TU250X Service Manual page 323

Complaint
Engine idles poorly.
Engine stalls often.
Symptom and possible causes
1. Valve clearance out of adjustment
2. Poor seating of valves
3. Defective valve guides
4. Worn rocker arms or cam surfaces
5. Too wide spark plug gap
6. Defective ignition coil
7. Defective CKP sensor
8. Defective ECM
9. Defective TP sensor
10. Defective fuel pump
Incorrect fuel/air mixture
1. Defective IAP sensor or circuit
2. Clogged fuel mesh filter
3. Defective fuel pump
4. Defective fuel pressure regulator
5. Defective ET sensor
6. Defective IAT sensor
Fuel injector improperly operating
1. Defective fuel injector
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 CKP sensor
6. Defective ET sensor
Engine internal parts improperly operating
1. Fouled spark plug
2. Defective CKP sensor or ECM
3. Clogged fuel hose
4. Valve clearance out of adjustment
SERVICING INFORMATION 10-3
Remedy
Adjust.
Replace or repair.
Replace.
Replace.
Adjust or replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Repair or replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Repair or replace.
Repair or replace.
Replace or recharge.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Clean.
Replace.
Clean.
Adjust.