This system is really insane.  How is the Cat connected to the ignition?
Smoky was making socially unacceptable noises so I drove to town, purchased
a new gasket for the Cat, drove home and up onto a couple of blocks to get
headroom, and changed the gasket.  Honestly, that's all I did - change the
exhaust gasket.

Went to start the engine to make certain I got the joint tight and --
nothing.  Turns over fine.  Won't fire.  Strong smell of gas.

Checked for gas leaks.  Nada
Pulled plugs on 3 and 4.  Great spark.  Both plugs wet.
Checked rotor position. Right on TDC for 1 and 3 ( Or is it 4.  Still not
confident on cylinder numbering.)
Changed the CPU for my spare which I know is OK.  Rien.
Checked all the electrical connections.  Everything connected.
Looked in the troubleshooting section of Haynes.  Couldn't see any helpful
checks or suggestions.

Soooo - If there is spark and gas and the timing is OK, why won't the
~!@#$%&* thing fire?

Suggestions most humbly and gratefully accepted.

Earl from Sunny Sooke
84 ex-California Vanagon