Misfires under load (acceleration) can be caused by leaky spark plug boots. When a spark plug boot leaks, it allows the spark to arc, or jump, to the cylinder head. New spark plug wires will be needed.
Mazda 323 Problem Reports
RepairPal Verified Mazda 323 Problem Reports
An electrically shorted air flow sensor can cause a crank-no start condition. Diagnosis may show that ignition spark is normal, and there are no trouble codes stored.
If the automatic transmission shifts in and out of overdrive while cruising, it may be due to the thermostat that is stuck open. The 323 transmission is especially effected by the engine running too cool. If possible, check to see the engine is running at full operating temperature while cruising. The temperature gauge in the 323 may also read normal when the engine is not reaching normal operating temperature.
If the engine cranks but does not start, and diagnosis shows no fuel pressure, the fuel pump relay is frequently the problem. If the fuel pump relay is defective, the fuel pump will not energize and therefore, not generate fuel pressure so the engine can run.
The timing belt tensioner pulley may make a squealing noise from the timing cover area on cold startup. An updated tensioner with a thicker mounting bracket to eliminate vibration may be needed to solve the problem.