Automotive Air Conditioning Information Forum

I recently converted my 90 Miata from R12 to R134-a. I've replaced all o-rings, the expansion valve and compressor shaft seal. After vacuuming I went to charge the system and got some strange results. I accidentally forgot to engage the AC from the dash so I added all 12oz without the compressor running and ended up with pressure on both sides at about 105psi (pretty hot day). I engaged the AC and the high immediately went to 0psi and the low to 130psi. What gives? No, I DO NOT have the gauges on backwards, I promise. Does this mean my compressor is shot? I also suspect my expansion valve may be trash, I bought it from autozone and when I received it you could tell it had been used, someone had put teflon on the fittings, installed it then removed it.

Oh also, compressor does not cycle, it runs constant.

handwheels on gauges closed?

Yes, closed.

Low side restriction.

Tim wrote:Low side restriction.

Please explain

So you bought a TXV from twilight zone, found TEFLON TAPE on it - and installed it anyway?

Yeah, that TXV is probably more like a plug than a valve.

How did you flush the system? What type of oil did you refill it with? Was the dryer replaced?

Yea I know, I shouldn't have installed it.
I used ester w/ dye and no I didn't replace the dryer. I know most people say it's necessary but I've seen many conversions where the dryer wasn't replaced and worked fine.