Automotive Air Conditioning Information Forum

You can not get an accurate temp using an infared thermometer due to emissary problems. Depending upon the reflectance of the metal the reading will vary. That is the reason why it is suggested to "shoot" an area that is black. If you shoot an area that is shinny, both in and out of the accumulator will be close. but not exact.

Dougflas wrote:You can not get an accurate temp using an infared thermometer due to emissary problems. Depending upon the reflectance of the metal the reading will vary. That is the reason why it is suggested to "shoot" an area that is black. If you shoot an area that is shinny, both in and out of the accumulator will be close. but not exact.

Good to know thx!

Thank you guys for the suggestions. I replaced the blend doors last year since they are a known issue on this model. They were replaced with aluminum doors with thicker foam. I have easy access to them so I double checked to make sure the actuators are operating like they should. Everything looks fine in there.

I started the car up this morning and the coldest it got was 62 at the vents. This was doors closed/recirc shaded carport and ambient temps around 78. Haha, I tried to play around with the ir thermometer and the temps were all over the place!

So I tried this after work, same shaded carport, outside temps 88. While inspecting the blend doors temp right at the evaporator 62-64 with the vent thermometer. Measured with the ir at the black plastic next to the evaporator and I got 63.8.

Going to read my service manual again to get info on my orifice tube. When I look up the hard line I ordered it states green orifice tube with a certain part number. When I looked up that part, my particular vehicle is not listed. I know my old orifice tube is blue. I can't id it based on these numbers. Definitely not the green I am seeing everywhere online. Ignore the cut section, it slid past the crimp and I cut right at that section.

Exactly what I was thinking, just a pain that you don't really know what you are getting with these replacement hard lines. This is what was inside the blue one that was working. Anyone seen one like this? The white orifice sounds and feels like a ceramic piece.

For identification reasons.

When poster mentions this site. They are not referring to this forum or its websites.

Tim wrote:For identification reasons.

When poster mentions this site. They are not referring to this forum or its websites.

Apologies, that's correct. My parts and information I was looking up were not from this forum or websites. I just didn't want to mention any other site names here.

Thank you.

Al9 wrote:Really weird look for an orifice tube, i swear i've never seen one like this before. The two differently sized holes on the front and the spring looking thing (rather than a single metal pipe surrounded by plastic and filtering media) lead me to believe that it's some kind of a variable flow orifice tube (look up patent US5081847A to understand how one works) but i could be wrong.

AI9, you are correct, its a VOV. I searched everywhere on the jeep forums and only found one post mention it. Made me realize that my service manual is 99-04. I bought a 99 specific service manual and sure enough that line contains a variable orifice valve. I was able purchase a factory line (which is discontinued). I will post up results once it arrives.

Thank you all for the help!

VOV's work better for low speed as in a mail delivery vehicle. For regular operations, just use a regular orfice tube. Superheat is not used in MVAC due to the ever changing conditions.

Just wanted to update. I received my factory hard line with the variable orifice valve and I installed it last night. Charged up my system and pressures and temps we perfect. As Dougflas stated the VOV definitely works better at idle and low speed. This is an advantage for me as this vehicle is for offroad and trails and driving slow most of the time anyways. On highway today I was seeing temps in the 46-48 range 88 outside and 90% humidity. At idle it was 42-44.

Out of curiosity, in the future if I ever need to do this again and went with a regular orifice tube, I would have to buy an orifice tube repair kit. If the OT I tried was .052, I would size down and experiment with sizes?

Greatly appreciate the help guys. It was a pain, but a great learning experience.