RE: R134 conversion

[Andrei Kogan <abk@phy.duke.edu>]

I had our 88 90q  converted to R134 this spring. The system was flushed and
the  receiver/dryer ($30) was replaced. The older system had a leak , so
the hose on the high side of the compressor was also replaced.  They left
the evaporator unmodified.

The system works fine.  The air is plenty cold at the vents. Compared to
the [ast, the differences are:

1.The hissing from the evaporator appears to be louder then before. 
2. It also keeps hissing  for at lest 10-20 seconds after the
engine/comressor is turned off. 
3. The car noticeably loses power when the a/c kicks in, but it's hard for
me to tell if the power loss is any bigger than before the conversion. 

Now, as far as I remember from reading the archives, 80/90 use an orifice
tube and not a TXV as  older 4000s do. I believe ideally one would replace
the orifice tube with something else when going to R134, not sure of the
reason, and the TXV doesn't need to be switched out. Regardless, the system
works for now and I hope I'm not destroying anything while using it.

If anyone can offer any comments/opinions regarding the R134 use in the
80/90 series cars please let me know.

Thanks,

Andrei