Automotive Air Conditioning Information Forum (Archives)

old honda on Wed June 22, 2011 12:09 PM

Year: 1992
Make: honda
Model: accord
Engine Size: 2.2l
Refrigerant Type: r134a
Ambient Temp: 85
Pressure Low: 25
Pressure High: 185
Country of Origin: United States

I am trying to diagnose the problem with my a/c.
All parts are original. The car has been without a/c for years.
I have injected dye & two cans of r134 but found no leaks.
The compressor runs but doesn't cycle except in the morning when it's cool out.
One line, I believe the discharge line from the condenser was very hot.
The system had been retro fitted years ago by a mechanic in order to charge & test it.


Thanks

mk378 on Wed June 22, 2011 1:52 PM

You may need a tad more refrigerant. Find the rated R-12 capacity and use that much 134a. If you opened any lines it needed to be evacuated first. Also it's a good idea to evacuate when leaked down to zero. As for finding it down to zero, there must be a leak.

What you have now, it should be at least somewhat cool inside. Compressor cycling usually means that evaporator temperature setpoint (40 F) has been reached. Is the low side line cold? Have you checked for reheating from the heater? It's normal for the line from compressor to condenser to be too hot to touch. It gets even hotter with a low charge.

Edited: Wed June 22, 2011 at 1:54 PM by mk378

bromodragonfly on Wed June 22, 2011 4:56 PM

Condenser outlet, or aka condenser 'disrcharge' shouldn't be too hot to touch. If the condenser outlet is not cooler than the condenser inlet, there's a problem with condenser heat transfer or flow.

As MK378 pointed out, a properly charged system that is working nominally will give you an evap temp of around 30F with 25psi R134A. You would lose a bit of efficiency with a retrofit. Are you getting any cooling at all?

When you say the compressor isn't cycling except in the morning when it's cool out, does that mean the compressor won't even engage when the ambient temperature rises during the day? Or does it run continuously?

And yes, if you opened the system to atmosphere, it is imperative that you pull a vacuum and evacuate before charging - at the bare minimum. Moisture is highly detrimental. And air will dry-hump your system into submission if it's present inside.

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