Please advise on A/C conversion

[David.Ullrich at ferguson.com]

OK, maybe my compressor is dying. The low side is a bit high, but the high side is about right (possibly a tad high). I too have vent temps of around 140 at startup, but it DOES take 10 minutes or so to get below 60*. Still bottoms out in the same range (47-50* on any day). Can anybody shed some light on this? Would a slight overfill cause it to take longer to cool down yet still reach the same terminal temp? Would the fact that I have a black exterior and he has a charcoal account for this difference? Or is it just acceptable variation from car to car? Why is it taking longer in my car, yet the terminal temperatures are the same?

Dave

Too Many Toys:
2002 VW Jetta GLS 1.8T Tiptronic
1993 RX-7 R1
1987.5 Audi Coupe GT "Special Build" 2.3 - Anthracite Black
1985 Chevy Impala Interceptor


-----Original Message-----
From: Roa, Greg [mailto:Greg.Roa at Cinergy.COM]
Sent: Thursday, July 18, 2002 2:44 PM
To: David Ullrich - 0018 HQ; quattro at audifans.com
Subject: RE: Please advise on A/C conversion


My 4kq is charcoal (more or less black), with grey interior, and no tint either.  Usually when I start the car at the end of my work day, I have a vent temperature of about 140 degrees.
Even with this, I have no problem getting the temperatures down very quickly, usually in less than 5 minutes, I have vent temps around 55 degrees.

My one curiosity, and a question for the list, is what regulates the compressor duty cycle?  Even with the very low high side pressures I see, my compressor still cycles on and off normally, as if it is on a timer.  What gives the compressor it's signal?


Greg Roa
Cincinnati, OH
86' 4kcsq
93' 90 CS
83' 944



-----Original Message-----
From: David.Ullrich at ferguson.com [mailto:David.Ullrich at ferguson.com]
Sent: Thursday, July 18, 2002 2:31 PM
To: Roa, Greg; quattro at audifans.com
Subject: RE: Please advise on A/C conversion


Yeah, my pressure seems OK. The high side is GREAT, but the low side actually a little too high IMHO (around 70 IIRC, but not sure). I think in my case, the time it takes is greatly dependent on the color of your car. My CGT is black with a black interior and no window tint. In the morning when the sun it not strong and temps are in the upper 70s, it will drop to 50ish within 4-5 minutes. It bottoms out in the 47-50* range you mentioned. But with R12 in it it was going down to around 40-42* before the high pressure flex hose blew. So, I think my compressor is OK, although loud (it squeals for just a second when it kicks in or turns off, not the belt). According to the TSB from Audi, York type compressors are not recommended for R134a conversion...who knows why.

Dave

Too Many Toys:
2002 VW Jetta GLS 1.8T Tiptronic
1993 RX-7 R1
1987.5 Audi Coupe GT "Special Build" 2.3 - Anthracite Black
1985 Chevy Impala Interceptor