when turn key to start the engine I hear big hiising sound or air release sound from engine side. No crank sound from starting motor also. Again when I try second time it starts normally. Problem occurs once in few days not regularly. Where to check? If starting motor starts we should here some sound.I never felt starting motor starts.
When it doesn't start, have a helper turn the key to the start position while you check for power to the smaller wire on the starter. It should have 12volts. If it does, the starter is most likely bad. However, the hissing noise confuses me. Make sure there are no fuel leaks.