Ford: 1993 mercury tracer, 1993 mercury tracer, mercury tracer

Question
Engine(1.9 liter) misses under load and has a rough idle. I also have notice the gas tank is building more pressure than in the past. Spark plugs and  wires were replaced about two years ago at approximately 12000 miles.

Answer
when you have a misfire under a load it could be several things first you need to test spark,fuel  pressure ,you may have a clog fuel filter,you may have a bad injector.or a low compression in a cylinder, when was the last time you had the trimming belt replace if i was more then 60,000 then you may have a problem there.