I have a 2005 Chevy Blazer 4.3L V6 4X4 with 147,731 miles on it. I recently fixed the ac in it because it had a blown line. I replaced the orpise tube, filter dryer, high side charge port the ac line they busted and gaskets. I’ve noticed that while going down the Highway the ac is warm and a lot colder when idling. All pressures are normal and correct. I’ve also noticed that the compressor will cut off when feathering the throttle. What could cause that?
You say the compressor is cutting out when feathering the throttle, could it also be cutting off when cruising at highway speed? Maybe the low side is going too deep into suction at higher engine RPMs? (The low-pressure cutout on most AC systems will turn off the compressor when pressure drops to about 20 psi or less.) What are system pressures with the engine cranked up to typical cruising speed, probably 2000-2500 RPM?
Did you pull vacuum on the system long enough to pull out air and moisture, and put in the correct amount of refrigerant by weight? A lot of AC systems are sensitive to any undercharge or overcharge, even a few ounces off can make them act up.
Then there's the issue of whether your temperature blend door is working properly.
Lots of variables here that can cause problems.
Assuming that the work is correctly done, the other things it could be are faulty vents or debris blockage, have you changed the filters in the A/C? Those can become a problem over time and are often not even looked at. Since your compressor is acting up, it is possible that you over charged the system. What set of gauges are you using? What's the pressure reading?
