Ralph wrote:
>
> As a follow-up to my original post, the problem has now been found. The
> compression test was redone using a gauge with a thread adaptor into the
> spark plug hole. This set of tests were good, between 160 and 165 on all
> four cylinders. The contents of the Catalytic converter have been removed
> and leaving the shell in place. Spark has been verified on all four
> cylinders. With the engine running, the ignition wire was removed from the
> #3 cylinder without any noticeable difference in engine speed. #3 cylinder
> was dead, but had good compression and spark. Ran the engine with #3 spark
> plug removed and the air expelled through the spark plug hole lacked the
> smell of "gas", just plain air. This is a carburetored engine, how can 3
> cylinders get fuel/air mixture but the one cylinder doesn't, that was the
> question. In close examination of the face between the intake manifold and
> the cylinder head (at #3 cylinder intake port), a small section of gasket
> seemed to have vanished. This was confirmed with a fine wire that could be
> pushed between the two surfaces. At high speed or under full throttle
> there is enough fuel going through the carb and the leak is small enough
> that the problem is barely noticeable. If the gasket gap had been on the
> bottom side of the intake manifold, it is doubtful that it would have
> been detected.
>

It sounds like you had a really bad vacuum leak. This could have been
easily detected by spraying carburetor cleaner on the manifold to head
junction or via a propane enrichment test.

Eric