I think it sounds like a low charge too,you can jump out the low pres switch and tell for sure,the 134a conversion kit at autozone does pretty good for the money,but you need a vacume pump too do it right

oh what a feeling:
#1 86 xtra cab 22R,EB 261 cam ,Hooker header,2" ex with cherry bomb, Aussie powered
#2 86 sr5 4x4 efi parts truck
#3 87 2wd parts truck
84 supra yard art