Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
What you are describing sounds like short cycling. If the compressor is cycling on and off and will only get cold when accelerating it is probably overcharged. Do you have a set of manifold gauges to test the system pressure and make sure it's not overcharged?
I'm sorry, is someone else already helping you via the phone call feature?
I thought you no longer needed help when I never received a response.
A bad blend door is definitely possible. When you change from hot to cold on the control head can you hear any change in the sounds coming from the dash? Clicking, movement, air flow differences?
So the compressor still kicks in and out?
Have you checked the orifice tube to make sure it isn't plugged? Does the airflow seem adequate or is the evaporator possibly restricted (do you own a dog-we see them plug up all the time in vehicles were dogs are frequent passengers)?