Likely your system is still filled with mineral oil. It is not compatable with r134. It will run, but only briefly.

R134 can't carry the mineral oil and thus will run as if there is little or no oil.

Why don't you just buy a couple of cans of r12 on eBay and be done with it?

__________________
Eugene

10 E63 AMG
93 300te 4matic
07 BMW X3
14 Ford F-150 Fx2