Tried adding freon with oil charge, but would not add any?

I just bought this dispenser Gauge where all u have to do is squeeze the trigger and its supposed to spray the freon in..well the can of freon i had was only 1 ounce 134a, 1 ounce refrigerant oil, and 1 ounce ice 32 performance enhancer...i didn't need that much freon bc i was already in the low green on my gauge with the car running on high ac. My car has been taking forever to cool off during the day(even then it isn't as cold as it is during night), so i figured i could use the oil and performance enhancer...well after i set everything up right..(i read the instructions over and over) every time i tried to spray it into the low pressure port, nothing would spray into my car..could it be a bad freon gauge or whats the deal?