1994 orface tube help

[2wdmuddin]

i think my orfice tube is clogged and needs to be replaced because when im moving the air works perfect but the second i come to a stop it starts blowing outside temp and i had some one tell me it could be the orface tube. if any one knows anything else i would appreciate the help. also does anyone know where the orface tube is and how to get to it on a 94 3.0?

 

[v8318cid]

I suppose its possible. Either that or you don't have adequate cooling on the condenser when the vehicle isn't moving. I'd suggest you check the condenser fan for proper operation. Otherwise, the oriface tube is typically located inside the lower evaporator tube. You have to have the system evacuated, then disconnect the line from the evaporator. Once disconnected, the oriface tube can typically be removed using either a pair of needle nose pliers, or a special tool designed for this purpose. Be advised that if you use pliers, DO NOT twist the tube or it could break off inside the evaporator. Not fun to fix at that point. Also, you may consider switching from a fixed oriface tube to a variable tube. On a 134a system, it can improve performance at low speeds/idle by anywhere between 3 and 5 degrees. Just a suggestion of course.

 

[slownis]

I've pulled the orifice tube on my '92 about 3 times in the last week. You should be able to get it out no problem with some needle noses, but like the man said, just pull, don't twist. Be sure you use 2 wrenches to undo the fitting. The fitting is just below where the accumulator is - almost looks like its attached to the bottom of the accumulator, but its not, it goes into the evaporator. Undo those bolts, move the line coming from the condenser away, and then you'll see the end of the orifice tube sticking out. Just grab it with the pliers and pull straight out. You may just be low on refrigerant. Have you checked the pressures?

 

[4x4junkie]

...you don't have adequate cooling on the condenser when the vehicle isn't moving. I'd suggest you check the condenser fan for proper operation.

This.



A plugged orifice would make the A/C not work at all.

Inadequate airflow over the condenser can cause the high-side pressure switch to trip, which shuts down the compressor until the pressure dissipates (or more airflow is restored).
A worn fan clutch and/or clogged condenser fins can cause this (also make sure the condenser is sealed against your radiator around it's perimeter, this so the fan can actually draw the air through it instead of around it)

 

[2wdmuddin]

I thought about the air flow because I've had a 2 piece fan shroud for a while but when I replaced it it still does the same thing. It could be the clutch but it turns like it should. Is there anything else that it could be? Thanks for all the help. I'm goin to check a couple more things

 

[Explorin94]

How cold is it to begin with when you are moving?

 

[press 1 for english]

1) Could be low on refrigerant causing short cycling at low engine speeds.
2) Could be a dirty condensor coil that needs additional air moving through the coil and that would explain the working OK when the vehicle is moving.
3) Could be a sticking compressor clutch assembly.
4) Maybe at low engine speeds the vacuum is too low and the blend door is opening. Vacuum leak.
5) Could be faulty high or low pressure switch.

Is the compressor engaged when the problem occurs, that would be nice to know. If the fan clutch were a problem the engine would be running hotter.