Engine & fuel system
3 documented faults — symptoms, causes and workshop fixes.
Failure to start
Overview
- Affects
- All models with petrol engines.
Symptoms
Trouble codes related to camshaft position (CMP) sensor stored in fault memory.
Cause
Incorrect valve timing due to timing belt wear.
Repair
- Check condition of timing belt. Replace if necessary.
- Check valve timing and adjust if necessary.
Data: Motorwise Workshop. Bulletin 1.
Poor engine performance
Symptoms
Trouble codes related to heated oxygen sensor (HO2S) stored in fault memory.
Cause
Mass air flow (MAF) sensor faulty.
Repair
- Fit new MAF sensor.
Data: Motorwise Workshop. Bulletin 2.
Engine misfire
Symptoms
Poor engine performance.
Cause
Intake air pipe between mass air flow (MAF) sensor and throttle body split or cracked.
Repair
- Replace intake air pipe.
Data: Motorwise Workshop. Bulletin 3.
Glossary
Technical terms used in this guide.
- Trouble Codes
- Standardised fault codes stored by the engine control module, read with a diagnostic tool
- CMP
- Camshaft position — a sensor that tells the engine control module where the camshaft is
- MAF
- Mass air flow — a sensor that measures how much air the engine is breathing
- Fault Memory
- The list of stored trouble codes in a control module
Frequently asked questions
What are the common faults with the Mazda 323 1.5?
This guide contains three workshop bulletins for the Mazda 323 1.5. Of these, three concern the engine and fuel system. Symptoms, causes, repair steps and part numbers are shown where supplied.
Does every Mazda 323 1.5 have these faults?
No. These are patterns documented across the model by workshops, not predictions for an individual vehicle. Where a fault applies only to certain vehicles or VIN ranges, that is listed with the fault.
Can I check for Mazda 323 1.5 faults myself?
Many of them. The documented symptoms can be seen, heard or felt during a test drive.