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Discussion Starter · #1 ·
I have a 99 ZX2 and the A/C recently started blowing ambient temperature air. I'm trying to locate the problem and need some help since it's not one of the usual suspects of A/C problems.

Things I know aren't the problem:
  1. A/C compressor, it's cycling and building pressure just like it should be
  2. Freon, I have a gauge it's well within the expected pressure range
  3. Blend door, the blend door is mechanical, so I can hear it moving and it definitely shuts off the hot air when I turn it to cold
  4. Any switches (pressure switches, CCRM, etc), as I said above, the compressor is running and cycling on and off just like it should
Where I suspect the problem is:
I measured the temperature of the lines in various places with an infrared thermometer after running the A/C for about 5 minutes. The high pressure lines (liquid line) right off the compressor gets up to about 135F and as labeled below in the picture, before the condenser it's about 115F, after the condenser is about 90F. All of this seems pretty normal to me at this point. But right before and after the hood switch, there's a huge temperature difference. Then by the strut tower it's starting to warm back up again. The low pressure lines on the other side of the car are whatever temperature the engine bay is.
Motor vehicle Hood Automotive tire Automotive exterior Auto part


Given all this, I suspect there's some sort of blockage and the Freon is decompressing (and cooling) before it should. Then it warms back up to normal air temperature by the time it gets to the evaporator. I took this apart once and found just inside the stainless colored line was this.
Hood Automotive tire Automotive lighting Motor vehicle Tread

(Sorry about the blurry picture). There's a vertical bar and a steel ball of some sort that appeared to be mounted in there, so I assume they're supposed to be there. This is where my knowledge of A/C runs out. There was also some foreign material in there, which you can barely see around the edges. I blew this out with my air compressor at 120 psi in both directions, which I thought did the trick but I still have the same problem.

My questions are:
  1. Does anyone know if that bar and ball are supposed to be there and what they do?
  2. Is it likely there's some sort of a blockage in that line I need to get cleared out?
  3. What else could it be?
I haven't been able to find this line anywhere (except RockAuto but the picture doesn't match the shape of this line so I don't really want to buy it just yet). I don't think there's much of a chance of replacing it.

Thank you for your help.
 

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Discussion Starter · #3 ·
That is the expansion valve. you should be able to pull it out with a pair of needle nose. note the color of the valve represents the orifice diameter
I did some searching around, it seems like this is more commonly referred to as an "orifice tube" and is used in place of a true expansion valve? What I've also noticed is that none of the orifice tubes on Autozone's website and others don't look like the one that is in the car currently, which has me a bit confused yet.

Example orifice tube at Autozone.
 

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Discussion Starter · #8 ·
yes. the reference is correct.. orifice tube is the modern nomenclature for expansion valve.. same principle. next thing... forget autozone completely. delete that from your memory. the 'orifice tubes' are all pretty much universally accepted by color. so once you get it out, clean it up and figure out what color it is. then you can look for the proper part. NEVER waste your time at autozone. thats like going to a proctologist for ankle pain. orileys carries these parts in almost every store. but you must know the color. its probably either blue, orange or white.
Thanks for confirming the orifice tube for me. Learn something new everyday. It must plugged up for one reason or another.

Also thanks for the unwanted advice on parts stores. I'm sorry your experience with Autozone hasn't been great but I've gotten a number of parts for free due to their warranty program which I have yet to see O'Reilly's match. Nothing against O'Reilly's, I buy things from there too and frankly I don't care where I go if they have the part I need.
 
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