I have an engine to remove in a 86-89 4runner and it's got an AC pump and I don't think the system has been drained of refrigerant. Is it possible to remove the pump from the engine and suspend it in the engine bay without discharging the AC system so I can get this engine out?

 

Yes, it has been done buy one or two guys on here doing 3.4 swaps and keeping the old 3.0 R12 AC system charged.

 

Sure it can be done. I have done it with several AC-equipped vehicles including my '94 pickup and the '94 pickup my old man used to have.