Car running with the vacuum line disconnected. Might want to cap off the line, but no vac to the regulator while adjusting. Set to 38-40. Generally, the computer will adjust to get the fuel ratio right but if there isn't enough pressure there will be low flow, which the computer can't fix if it's out of the limits.
this is the correct way to do it, capping the line isnt neccessary but wont hurt. just to clarify i wasnt trying to be a dck before, just would hate to see you hurt the motor for a dumb reason. At first when your wrenching on the car it seems pretty intimidating if your not familiar with it, but these cars are pretty simple, and generally not too fussy once they are running good. Just a handful of sensors and fuel pressure and timing to worry about. Also the fuel filter is important especially with the inconsistencies of pump gas. If thats gummed up forget about it