[V8] "93 V8 hard to start & no RPM

[Richard Hill]

Hey you Guys ,
 
A few days ago the "93 4.2 V8 ( daily driver of mine ) deceided to act up .
     My wife used the Audi to go to the post office & to pick up our grandson . When she returned home the idle seemed rough.  I got in the car & NO-POWER / NO RPM's
The engine seems like it's dieseling and you really have to work the gas pedal to keep it from stalling out /  once in a great while the RPM's shoot up to 2500 or 3,000 for an instant.   Exaust smells of raw fuel...  Has the O2 Sensor crapped out ?
 
Need help with diagnosis..  TIA  Rick Hill in the U.P. of MI