Cadillac Repair: 1990 sedan deville, fuel mileage, correct signal

Question
1990 sedan deville runs god cold,then warms up and starts running rough, fuel mileage drops to 20% of normal consumption, lots of raw fuel.Now on start up runs a little rough, i suspect the plugs are wet, I've heard fuel injs, throttle body carbon build up, o2 sensor, and ECM as possibilities for failure, with out a o-scope is there any to tell if the injectors are getting then correct signal from the computer? what does this sound like?
                        thanks
                           EZ

Answer
Check your air filter, and the ground connection to and from the battery.
If the plugs were wet it wouldnt last for more then a day or two of normal driving, but you may have oil on the plugs, i would reccomend taking one out, and checking it for oil and the wear on it.