Engine AC blowing cool not cold

93CalypsoConvert

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Nov 26, 2020
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I installed a 5.0Resto r-134a kit for 87-93 mustangs. Made sure system was prepared (flushed evaporator core, oiled everything, pulled and held vacuum, continued vacuum for additional 45 min), then I charged with the required 24oz of 134a, but the thing will only blow cool, but not cold (vent thermometer says 60 degrees). Also, the compressor never cycles off, it puts a substantial load on the engine, and makes the whole car run about 30 degrees hotter. Is there too much refrigerant in the system? Bad compressor? I doubt its an orifice tube issue since everything was flushed or new. I am not sure what to do here.
 
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nickyb

WAIT,you now have a pair?
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Apr 3, 2009
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A set of gauges will help tell you what it is. H.F. Has a cheap set.I personally used e.s.12a and years later I still get below 40 degrees and that is here in Nevada,aka surface of the sun.
 

Potomus Pete

Gretchen Whitmer is eating at me
Mar 7, 2019
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Frosty Cool 12a would do it...Or you didn't clean enough...I did mine, but didn't clean enough.Has to be super clean. See if your orafice freezes up
 

KRUISR

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Apr 16, 2015
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Is your fan moving enough air across the condensor?
 
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93CalypsoConvert

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Nov 26, 2020
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A set of gauges will help tell you what it is. H.F. Has a cheap set.I personally used e.s.12a and years later I still get below 40 degrees and that is here in Nevada,aka surface of the sun.
Ok re-rented the gauges I used when filling the system...

Here is my static pressure at 80 degrees:
Static.jpg


Here is my running temps... Low side stayed between 30 and 40 but high side jumped to 210 but kept climbing and climbing until I shut it off at 340.
Run.jpg


Here is what the vent was saying:
Vent.jpg


I have no clue what to make of these numbers... Really hope its just overcharged:shrug:

Ran the system for about 10 minutes at 1100 rpm with my massive shop fan at full blast blowing into condenser.
 

93CalypsoConvert

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Nov 26, 2020
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Update: Tested the system and while running some water over condenser to cool it. Pressure went back down to where it should be so my problem was airflow across it. Went out and bought an auxiliary fan and mounted it to the condenser. Set it up on a relay to activate off the compressor clutch. Blows 37 degrees out the vents now.
 
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Mustang5L5

Put lubricant all over the balls
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Update: Tested the system and while running some water over condenser to cool it. Pressure went back down to where it should be so my problem was airflow across it. Went out and bought an auxiliary fan and mounted it to the condenser. Set it up on a relay to activate off the compressor clutch. Blows 37 degrees out the vents now.

glad you found it. I was going to chime in when I saw your pressures and say that there are typically too causes of a low side pressure being too low, and hugh side being too high. One is overcharged, which I don’t think you were. Second is poor airflow through the condenser.