1989 Ford F-150 Rough Idle

While driving along the truck seemed to loose power. At a stop the idle is rough and engine acts like its going to stall. The fumes are bad, smells like it is burning rich. The check engine light also is on (didn't think it even worked).
Replaced o2 sensor. No change.
Went to work on again and wouldn't start, changed plugs and it started right up but still had original problem.
Went to work on the next day and wouldn't start, changed dist. Cap and started right up with the original problem.
Today it won't start. Changed ecm and fuel relay, have fuel past the filter but not sure of pressure.
Not sure where to focus my trouble shooting.