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Old 06-07-2016, 06:28 PM   #1
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Default A/C CYCLING ISSUES

Hi I have a 1994 olds 88,I recently installed a used compressor and I pulled a vacuum and it held. I also recharged to spec low side and high within range. Problem is the a/c cycles continuously while at idle around 100orpms. cycles on and off at above 1500 rpms. is this normal for this car?
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Old 06-07-2016, 08:10 PM   #2
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It depends on the temperature, humidity, and the pressures you are seeing. That car does not have a variable displacement compressor so the only way to control system pressures is to control whether the compressor is running or not. Is it getting cold?
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Old 06-07-2016, 10:09 PM   #3
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Would like to know what the pressures are, when it cycles off....if the low side is dropping to 25 PSI, then you need more freon....
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Old 06-08-2016, 09:56 AM   #4
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Yes its getting cold but not like it was before. I also changed the orifice tube. I have attached a picture also of my low side and high side pressures while a/c is running. The other question I have, would the orifice tube be reason my a/c is not as cold as before because I have climate control and after doing research I found other orifice tubes that are listed for climate control systems. I bought el cheapo tube for a couple of dollars.
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Old 06-08-2016, 10:52 AM   #5
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I forgot to mention the outside temp was 80 on this day
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Old 06-08-2016, 11:12 AM   #6
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What is the actual vent temperature?

The pressures seem to be where they belong. At 80*, I also notice compressor cycling on both cars off of idle, and it doesn't seem like the A/C is as cold as it necessarily should be, but as the temperatures go up, the A/C seems to work better.

If this is your first round of A/C this year, and it seems to be getting the job done for the moment, I would consider leaving it, and then messing with it only if it reaches the point where it isn't getting the job done any more.

It may also be a good idea to verify the airmix actuator is functioning properly, as that is also a known problem area on these cars. If it'* not swinging full cold like it should, then that can also cause grief.

I don't know what effect the orifice tube would have on cooling in this application however, I haven't had to dive that deeply into an A/C system just yet.
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Old 06-08-2016, 11:29 AM   #7
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Those pressures look good.....as rjolly87 asked, what are the register temps coming out? If 50 degrees or less, running ok......If higher, check temp door operation.....is this dual zone, or auto temp?

If auto temp, to get a true reading of register temp, have the setting at 60....that is max cold...-

Remember, this is not a variable displacement compressor......it will cycle, under certain conditions, for example, when pressures reach it'* cutoff pressure....this is normal......

What you don't want, is to see it constantly cycling on/off, in a short period of time....

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Old 06-09-2016, 11:51 AM   #8
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Thanks for the help turns out I had a leaking valve stem on my drier where the pressure switch goes. Fixed that and now I have good cold air.
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Old 06-09-2016, 03:48 PM   #9
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I hate those! Especially because they don't fail until you have a full charge in the system, causing you to lose the charge.

Glad you got it squared away, hopefully your summers are frigid for years to come!
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