Thanks. I'll start with checking out the vac lines.

 

I would be "HIGHLY" be suspicious of a vac. line that is "soft" in an area (possibly neer/against an item that could get warm or hot) therefore softening the vac. line and/or when vaccum builds it sucks it's self in as if it were "pinched off". Also when a vaccum line is to soft in an area it could have hairline cracks along it, If any line is "suspect" just eliminate all doubt, vaccum lines are cheep enough yet, seem to be one of the items less desirable to flock with. Take the time & get the correct size replacements! Keep us informed.

 

Sounds like a vacuum leak, for sure, or stuck relay would explain the time delay? I would follow the vacuum line coming from the intake to a 'T' valve, or 'one-way' valve, and check the two attached hoses... one side goes to the vacuum resevoir inside the fender near the brake booster, the other small hose connects to a wiring harness and runs through to your vacuum actuator. 5/32" hose dia you can get for 20 cents.