That is a
REAL SHAME... because the
MOST LIKELY
source of all your troubles is the 17 year old seal
on the front of that compressor...
Now
opening the system... you have let in atmosphere...
(means
ANY moisture).
If your system works at IDLE... it is working
WELL...
Right now my BEST GUESS is that you did not pull a
full vacuum... and hold it for about 45 minutes...
((intended to EVACUATE & DRY out your system))...
Check out the ROBINAIR vacuum pumps
on AMAZON...
OR (used)...
If the SELLER says fully functional... It is a protected
purchase (eBay guaranteed (have a look)) :
ROBINAIR COOLTECH 15400 Vacuum Pump eBay
Of course you are on your own getting the R12/22
fittings to
adapt your R134a fittings (
type... MAYBE
(you
MUST check vehicles
LABELS yourself...!!)
I am just saying ICE in your expansion valve
is what is KILLING YOU (my opinion).
Hope this helps
en.wikipedia.org/wiki/carnac_the_magnificent