jronald

93 ZJ has the expansion valve located roughly 6 feet from the evaporator core. For those who dont know, its located at the exit of the Condenser, in the hardline that runs along the inner passenger fender. Would it not make more sense to have the orifice tube located much closer to the evap? Say on or at the firewall?

Whats your opinion?
Ron

lurk520

Yes you are correct, otherwise the refrigerant is going to absorb a bunch of heat from the engine bay before it even reaches the evaporator. I have studied HVAC for 2 years now and am currently working for a heating and cooling company. While automotive is a little different, it still would not make since to have the TXV right at the condenser outlet. I wonder how it got there?

lurk520

Not to mention the pressure drop this causes is probably making the compressor work a lot harder. Can you post a pic?

jronald

No pictures, but OT is inserted into the end of the hardline, where it connects to the condenser.

Here is a bad picture of the line
http://www.jeepair.com/air-condition...e-tube-742.php
The firewall is on the right, the condenser on the left. Looking close on the left you will see the line is larger both before and after the "bend". After the bend but before the line shrinks down, is the Orifice tube. As the line runs, its at least 4 or 5 feet, before the evap core.

Ron

jnicewan

Expansion valves and orifice tubes are 2 different things, you either have one or the other, these use orifice tubes as you already know.

They put them out there because most people would complain about the noise the refrigerant makes passing through the orifice. At least this how it was explained to me by a engineer from Ford. You normally dont hear it under the hood unless you shut the engine off and walk in front of the vehicle. Exapansion valves are almost always tied to the Evaporator, by design they ned to be and unless the system is low you normally dont hear them work. You could always get some cork tape or insulation to wrap around the line too.

Bustedback

The orifice tube on our ZJs can not be replaced, you have to replace the whole hard line. I put split loom over the hard line on my ZJ, I didn't notice any difference in the air duct temp though.

jronald

Here is what Im pondering, after removing the factory one
http://www.compressorworld.net/ecommerce/mt1049.html
http://www.autoacsystems.com/_store/detail/A3556.html
http://www.oreillyauto.com/site/c/se...003&vi=1414998
Worst case it can go after the service port on the firewall. Best case it can go in the portion just before the inlet.

Ron

lurk520

Exactly what I was going to say.....