Horrible Misfire/Idle Problem/Spark Plug Problem
 

The 1993 GMC Jimmy has been idling very very rough. When you crank it there is a very apperant smell of gas, the exhaust smells really bad, the spark plugs are covered in a black soot, and it gets horrible gas mileage. The exhaust is so bad that when you crank it and let it idle, the grass under the tip will turn black. It sounds like it has a big ass cam in it.
How do I fix this?

RE: Horrible Misfire/Idle Problem/Spark Plug Problem
 

Sounds like either the catalytic converter has gone bad, or you have an internal fuel leak. Is this a CPI motor or TBI? I'm leaning towards an internal fuel leak, but if an internal fuel leak is allowed to go on too long, it will lead to converter failure.

RE: Horrible Misfire/Idle Problem/Spark Plug Problem
 

Converter has already failed and has been cut out. It's CPI, I think.