Air conditioning is blowing hot air, system fully charged compressor is woring

Could be a damper stuck or not responding. If it keeps air going through heater core, you'll never feel cold air.
Have you verified the compressor clutch is engaged and compressor turning?

I would suspect the AC compressor cycling switch (located in low pressure line from compressor) or a AC cutoff wide open throttle relay ( in under hood fuse and relay center) would be causing this problem.

try charging your ac system

Air Conditioner blows warm air

1. Air conditioner system is discharged. Have the system evacuated, charged and leak tested by an MVAC certified technician, utilizing approved recovery/recycling equipment. Repair as necessary.
2. Air conditioner compressor clutch not engaging. Check compressor clutch wiring, electrical connections and compressor clutch, and repair or replace as necessary.

did you over charge system does compressor come on. if you over charge system it will not engage compressor and if compreesor comes on might check blend air doors to see if it is working properly

OK, this is air-conditioning 1-0-1

You say that i holds a charge, and the compressore turns, but does the comprressor cycle on and off, as this is indicating that there is enough charge, and once there is low pressure detected, it turns the compressor on, and when it reaches a high pressure, the compressor cycles off.

Lastly, when engine running and AC on, if you feel the 2 pipes going in to the firewall, one should be hot, the other should be cold ???...is this happening ???

Do you hear the air conditioning compressor switch on (with the engine running) when you turn on the air conditioning from inside the car. Get a friend to turn on and off the air conditioning while you listen with the hood open engine running you should hear a clicking sound on and off each time the a/c is cycled on and off or the a/c clutch is not locking up the compressor. This may be due to many things (bad clutch, bad compressor, no power to controls or compressor clutch) but it could be a sign of low charge the system has a low pressure switch which prevents the system from being energized if the system has low refrigerant charge. By protecting itself it prevent catastrophic failure of the compressor and ensuing damage to the rest of the a/c system if the system looses it charge. You will need to have the system checked out by someone experienced in air conditioning work who will attach pressure gauges to your car and see if the refrigerant pressures are OK. The system naturally looses some refrigerant over time but if the system constantly looses charge then it has a leak that must be investigated and repaired before just recharging the system

Hopefully you used a manifold gauge and wore the proper eye protection when you charged the system with R134a .
Bring it to an a/c repair shop Unless you have the proper testing equiptment this is a costly and dangerous adventure.
Likely causes anyone of the sensors in the system,defective compressor,defective on/off switch,defective relay, fan and lastly a leak.
Trust me take it to a repair shop yes a/c systems repairs are costlybut worth it.

Can't go by the pressure. Ck the large lone coming out of firewall, should be col. Small line at ac condensor in front of radiator should be hot.

Static pressure on high side probably 80psI Running 30 on the low side and 1130. will vary depending on oiutside temp Hope this hekoped

Check your pressures again. Jump the pressure switch and see if this makes the compressor come on. If it does then jump it long enough to get some more freon into the system. This should give switch enough pressure.

Make sure your vacuum is good on the system before you fill.