One the end of the Injection Pump facing the firewall, there is a brown vacuum line connecting to the fuel shut off. It goes through the firewall to the vac. valve on the end of the ignition switch.
A second brown vac. line is the vac. source and it to goes to the ignition switch.
Check to see if you knocked one of those off.
There is a mess of vac. lines inthe area above the oil filter housing, can be confusing trying to figure out what line goes where.
The large black line, comes from the vacuum pump to the brake booster. then vac. is pulled off it to the various systems.
green line is for the climate/AC stuff.
Yellow line supplys the vac. storage under the rear shelf. and a second yellow line goes to the Drivers door for the door locks, trunk and fuel door.
These two lines come off a yellow check valve at the firewall.
I agree you must have air still trapped in the filter or lines from disconnecting the fuel line. the fuel pump or lift pump is down on the side of the Injection pump. you will see either a black cylinder or a round flat knob. If the black one, just pump it up and down, If the other unscrew it, it will pop up and just push it up and down to pump fuel from the tank to purge the air from the system. then push it down and tighten the knob.
I don`t know if I would want to use my hand to block off the air to kill the engine. If you pull the U-Tube to the Turbo and put your hand there, the suction could pull your fingers into the impellers of the spinning Turbo.
Charlie