[Mudcat]

Have you put a vacuum guage on it yet?

 

[Mudcat]

Put a vacuum guage on it and it might lead you in the right direction. Go here for some nice illistrations on vacuum readings.
http://www.users.bigpond.com/ergoff/vac1.htm

 

[Mudcat]

Probably not, just coincidentel. The delay is probably a weak or sticky sending unit. Try a little Marval Mystery Oil in the oil and gas, it could help clean things up.