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Rapid cycling

rschmitt2 on Thu April 29, 2010 9:36 PM User is offline

Year: 1992
Make: Plymouth
Model: Colt Vista
Engine Size: 1.8
Refrigerant Type: R134a
Ambient Temp: 67
Pressure Low: 46
Pressure High: 100

I replaced my compressor and dryer, pulled a deep vacuum and added 25 oz of freon.

When the compressor starts, the low side takes about 3 seconds to rise from 10 psi to 46 psi, then the compressor shuts off. Pressure drops to 10 and stays there about 7 seconds, then the compressor kicks on again. This cycle keeps repeating. When the compressor is on, output air is cold. Is my freon at the right level, and what causes the rapid cycling?

Edited: Thu April 29, 2010 at 10:00 PM by rschmitt2

mk378 on Fri April 30, 2010 9:05 AM User is offline

First it's a TXV system, it should not cycle on pressure. There's a cutout when the high side hits about 450, which should never happen in normal operation. Do the condenser fans work? What is the high side pressure doing? Second your description makes no sense, low side should drop as the compressor runs and rise when it stops. What is the rated R-12 charge? You should use close to that amount of R-134a.

rschmitt2 on Fri April 30, 2010 9:31 AM User is offline

R12 capacity was 30 oz. I thought you were supposed to use less R134, but I can add some more. Condensor fan is working ok. When the low side is going the up and down, the high side is around 100.

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