Look, there is a simple place to always start, and this is assuming that you don't have a Mityvac YET (you will need one).
We'll assume you have brakes, as usually folks do.
*First, find the main vac line from pump to brake booster.
*you vac line may have one or two "T"'s coming off of it
*from one of those, find the lines that go back to firewall just next to brake booster
*Green is to climate, Yellow is to door locks, yellow w/ gray stripe to vac reservoir, brown to ignition shutoff, and black just vents under dash.
*Unplug green and both yellow lines and plug the connector they came from. The lines going into the firewall can just sit there.
*Now start the car and let it run for a couple of minutes, then try and shut it off. If it shuts off, then you have a leak either in the climate control vac lines, or the door lock vac lines. Attach one at a time, let motor run and shutoff again. You can find the offending system that way.

if you still don't shut off, report back. Then it could be vac pump, shutoff valve, ignition switch piece, loose brown line to ign, or from ignition to shutoff on back of IP, to name a few.

Also, if you have a second "T" off the vac line, you may have to plug that one also for this test.

Report back......

__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John