2001 Dodge Ram 5.9L A/C Issue

[rljt60]

Friend’s wife complained A/C dies five minutes out from house. Hooked up gauges and A/C runs fine at idle. Raised RPM to 1700 and low pressure side dropped to 20psi and compressor clutch released and did not re-engage. Symptom of low R134A. Then discovered Hi pressure side schrader valve was steadily leaking gas. Didn’t notice any oil or residue around the valve. Replaced valve and vacuumed system.

Due to math error on my part I probably overcharged system but later bled off some gas. Now, start the car and at idle have 30psi low and 230 hi. A/C runs fine at idle for extended period (~10 minutes) but when raise RPM to 1700 low side drops to 20psi and compressor cuts out. Then psi rises to around 70 (trying to balance with hi side) and compressor kicks back in and runs fine. Hi side psi is around 225. Sounds like it is working right.

But, then turn car off and wait one to five minutes and turn it back on again and A/C will not start up again. Have to wait 15 minutes or so before A/C will start to work again. Balanced pressures are 70 to 90 depending on how much gas I bled off but symptoms are the same. No additives other than Dupont 134A have been added to the system. Doors and windows are open, max blast, and 90 degree ambient
and 60% humidity. Any suggestions?
Many thanks, Bill

[Chris Stewart]

Sounds like a blocked up GM oriface tube doesn't it?
I think the Mopars have a expansion valve doesn't it? Do they get blocked up?