I have a 95 Lt1 M6.. So this all started when I had a leak in a hard line. I replaced the line. In order to locate the leak i had charged the system with some UV detectant.. which happened to have sealer in it. I think this sealer.. caused my expansion valve to malfunction.
So.. the expansion valve wasn't opening.. which is why my compressor wouldn't kick on.. didn't know this at the time.. so I jumped the compressor where the relay is and forced it.. this over pressurized the system and cause the "safely blow off valve" to blow on the back of the compressor.
So.. I replaced that, and the drey.. evacuated and charged again. Then.. the compressor was working on it's own.. but.. it would stop cooling when I was on the hwy and only cool at traffic lights.. and in traffic. So i thought maybe it was freezing up.. I only had two cans in it at this point. So I added a 3rd can and that did no good. I put the gauges on the system and the pressure looked to be way too high on the low pressure port.. So i replaced the expansion valve AGAIN. Now.. I'm again not able to get the compressor to operate on it's own.. with the jumper in place it cools great.. but it will not come on via the relay. I've reset the PCM several times. and switched relays around. On the low port, with the compressor off the pressure is between 60-90PSI, with the compressor activated (via jumper) it goes down to around 45-50 which I believe is supposed to be ideal.. any ideas? I've been working on this thing for nearly a month.. getting frustrated.

 

http://lt1tech.com/

 

That's not nice.. I'm posting on the forum that has the most traffic because I've posted other places (camaroz28.com) and.. not many A/C experts there..

 

You may have contaminants in the compressor. There is valving in the newer compressors to help them redude parasitic load on the engine while cruising. I've seen a few compressors that would fail to build up correct pressure on the high side from this. Not shure what year GM started this.

 

Your pressure should be 35 to 40 on an r134a system. Do you know anyone with a OBD2 tool that you could check what the status of the pressure switches are? Your kind of shooting in the dark without that.

 

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His car is a '95, its a OBD1. Hence the reason the post should not be here. There are places in this website for LT1s,
https://ls1tech.com/forums/lt1-lt4-modifications-31/

I'm not trying to be a dick but this website is slow due to the useage per
https://ls1tech.com/forums/user-support-resources/697907-frequently-asked-questions-problems-read-before-posting-any-questions.html
and stuff like this keeps it slow.

 

I think you might be on the right track. My dad has an autoxray 5000 scan tool but he lives 4 hours away.. Could one at Autozone or O'reilly that you rent tell me the same thing?
I put the gauges on today.. and intermittently.. the high pressure port will climb all the way up to 450lbs (at least that's the max my gaugues go.. so I shut it off right away.. Then some times it runs normal.. 50lbs/250lbs and when it's running normally and I rev the car, the low pressure goes down and the high pressure goes up.. which is good I think.
I've done a little research on remanufactered compressors.. and decided there is no way I will buy one.. I'd like to put in another delphi.. if it needs replacing. My question is.. there is a board member that has a used one.. what are the chances that a compressor that has been off a car a while (hopefully plugged up) will be any good?