Automotive Air Conditioning Information Forum (Archives)

Coconut Sunrise on Mon May 13, 2013 9:53 PM

Year: 1992
Make: Honda
Model: VX Civic
Engine Size: 1.5
Refrigerant Type: 134a
Ambient Temp: 85
Pressure Low: 37
Pressure High: 240
Country of Origin: United States

First of All, I Greatly appreciate any Help I can get with the Daily Driver Civic Here in Miami. I have A 1992 HONDA CIVIC VX ( WHICH IS LIKE A HIGH FUEL EDITION) 47 MPG.
I do not Know if the VX model has anything to do with it I will return to that Question in a Moment.

The car had 225 k on it running r 12 factory system that had a Small leak requiring a a Little R12 every Now and then, The vent temps Never have been less then 50 degrees running at Highway speed 2200-2500 RPMs.

So I was involved in a front end Fender bender that involved the Hood and radiator support so I opted to just replace everything, including the factory Line across radiator support.
So I replaced
Condenser (new)
Drier (New)
Evaporator and Expansion Valve (New)

Flushed lines with A/C flush, Added the New O rings and Connected all the Parts.
I left the current original Factory Compressor in place ( Prob Mistake I know but Funds are short )
Vacuumed it down with a Robinair 5 cFM dual action to -30 for one hour and Held Vacuum overnight.
Filled the System with 19oz of 134a and 2.5 Oz of Pag 46 Oil with Dye. (for any future issues )
Site Glass essentially pure no bubbles maybe one every once and awhile.

Vent temps best I have seen is 52 degrees with outside temps 80s on cabin recirculation !!! humidity running in the 84% range
Checked Heater valve clamped it and No difference in temps
1) Why cant I get a vent Temp in the 40s ? my TDI wagon sitting Next to it will pull a 38 degree vent temp !!!
2) Should I buy new Compressor ? one that is Rated 134 A since this is Original factory installed Compressor was R12 ? 225 Miles
3) Since this is a VX high Fuel model Do you think Thermostatic A/c Switch is retarding the the compressor at speed ? I cant tell if it is cycling at Speed.
It Does Not Cycle At 2500 RPM while parked....

Anyway thats My Story Any Advise will greatly Appreciated

Coconut Sunrise

mk378 on Mon May 13, 2013 10:44 PM

Too much oil. You really needed to drain the compressor, and optimally flush the evaporator, while converting. Mineral oil just gets in the way in a 134a system and impedes cooling. Using PAG in a system that may still have traces of R-12 (it stays in the oil) is asking for trouble.

Also scroll compressors tend to get tired and not pump very well with high miles. The higher condenser pressures of 134a require more from the compressor.

webbch on Wed May 15, 2013 5:30 PM

I'm guessing it's a comparable A/C system to the '92 Accord I had up until late last year. I parted with it at about 295k miles. I drove it in AZ weather for 7+ years. After I replaced the TXV and used prestite tape to tape the bulb to the evap, the peformance improved a LOT. Even after that, however, I would consider the performance "barely adequate" in hot weather climates, although vent temps were closer to 42 or so after the fix. I kept it R-12 though the whole time.

EDIT: I just looked, and I had also replaced the evaporator at that time, after finding it had a slow leak.

Edited: Thu May 16, 2013 at 3:26 PM by webbch