Sorry to be a wet blanket but I have this to say before we get started.
AC system repairs should not be attempted until your have diagnosed and confirmed the possible causes.
Knowingly discharging freon into the atmosphere is an offence and a recovery machine is required to carry out the work.
I would need some additional info to understand the problem better.
1. What are the low and high pressure readings for the AC at idling speed and when engine is held at 1500 rpm?
2. Does the compressor stay engaged all the time the AC is not blowing cold?
3. Is the air from the blower strong all the time or does it slows down when the air starts blowing warm?
4. The air that is not cold, does it get warm or hot as if the heater has been turned ON?
5. Are the cooling fans working?
6. Does controlling the coolness have any effect?
7. Does it blow cold at initial start up of AC?