viva air con

[lout]

2007 viva, trying to diagnose an ac system that is not cooling
compressor clutch engages, no unusual noises, has gas, both pipes to tx remain same temperature
so either weak compressor or tx valve stuck open
any thoughts to eliminate one or the other
aircon specialist says weak compressor, my gut says tx

 

[shane_3800]

2007 viva, trying to diagnose an ac system that is not cooling
compressor clutch engages, no unusual noises, has gas, both pipes to tx remain same temperature
so either weak compressor or tx valve stuck open
any thoughts to eliminate one or the other
aircon specialist says weak compressor, my gut says tx

You really need to see the pressures to diag it.
Is the TX easy to get to?

If the TX valve was working you would see it spike in pressure than drop off on the high side.

Some compressors also have an internal over pressure valve that dumps back into the low side. Could have a blocked TX and is dumping pressure back into the low side.

 

[lout]

there is not any appreciable rise in pressure on the high side

 

[shane_3800]

there is not any appreciable rise in pressure on the high side

Even if the the TX valve is wide open there should be a rise on the high side pressure.
I would try spin the compressor by hand with the belt off and see what it feels like.

 

[Jeda]

Give the TX valve a few persuasive cracks with a hammer. It might be stuck.

If the compressor is engaging, and there is gas in the system, you should feel a discernible temperature difference in the low and high pressure pipes while the AC is running. Get someone to assist you and hold the engine rpm at around 2000, If they're both hot, I'd be looking for tell tale signs of leakage around the crimped areas of the hoses. There may be gas in there, but not enough to do anything. If no leaks, I'd be testing the compressor. When was the last AC service you had on the Viva Las Vegas?

 

[lout]

sorry forgot to upgrade this post
there is a bypass valve inside the compressor which had failed open
aircon tech replaced just the valve and regassed $200