TXV Woes

Ok I had a no cool call the other day that has been giving me trouble. I found a bad condenser fan motor and a dirty evaporator coil. Cleaned the coil and replaced the motor. Turned the unit on and it purred like a kitten. pressures where spot on. The unit was cooling great. I leave and go to two more calls, and the shop calls me and tells me the customer called and the unit quit cooling. I finish the call im on and head back over there the compressor wasn’t running. I ohm it out and all is good so I turn it on and it is running. I notice that the suction line is not sweating now and reach down and feel of it and the liquid line and they feel to be about the same temp. I go to the truck and get my gauges hook them up and I have a very low suction about 38# and the liquid line pressure is about 184# which was standing pressure for the current outdoor ambient of 96 degrees. next thing I know the compressor starts bypassing and then trips on overload. My first thought was a compressor valve issue. I cooled the compressor off tapped on the top of the compressor a bit and turned it back on. Pressures where the same so I jarred the condenser a little, and the pressures went back to normal. So now im definitely thinking compressor valves. I inform the customer that if it happens again we may have to replace the condenser since it is r22 unit. Another tech and a helper go out there a few days later and he checks to see if he can get it to pump down and he determines that the problem is a bad txv so he goes and gets an r22 valve and replaces it. This was friday and as far as i know the unit is still running. My problem is that I have never seen a closed down txv that didn’t have a high liquid line pressure an low suction and I havent seen one make the compressor over heat. Freeze the Evap. coil yes. and never one that would work intermittently. The liquid line pressure not changing is what led me to believe that the problem was the compressor and not the txv. Can someone explain to me what is going on. Thank you
TXV Woes

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