Where's my vacuum gone? (Longish)

["D. Dardalis" <dardal@xxxxxxxxxxxxxxx>]

At 12:29 PM 2/19/2002 -0500, you wrote:
>There is not enough
>vacuum generated while I am cranking the engine to operate the vacuum motor
>that closes the restictor.
May be your starter is weak and can't turn over the engine fast enough to 
generate manifold vacuum.  If that's not the case, its quite likely that 
the cam profile of your 413 is a lot more "aggressive" than your Caddy's, 
so the vacuum is by design lower.  If its the second, there is little you 
can do about it.  Why don't you just fire up your car on gasoline, and once 
running switch to propane?  I can see the advantage on starting with 
propane to avoid rich gasoline mixture, but sometimes, we can't have it all!
D^2