1995 Mercury Tracer Rough Idle

I have had the same issue and still do to an extent with my 98 Tracer. From my own experience I'd check for a vacuum leak, spray the vacuum lines with carb cleaner you'll find your leak (I did anyway) when you notice the idle jumps up a bit. I also replaced the IAC, timing belt, motor mounts, A/C and even had a compression test done.

I hope this gives you some ideas, I don't know if your car has one but if it has a timing belt and not a chain I'd have the belt checked out. That is assuming you haven't already or it hasn't already been replaced in the last 60,000? Mine slipped a few teeth and did exactly what yours is doing right now, it finally just died luckily after I drove it to the shop! I think it cost over $300 for the job. If it turns out to be your timing belt insist on having the tensioner replaced at the same time you might even consider having the water pump done too assuming it's the same as the 98 model.

Thanks. Will look for vacuum leak this weekend. Tried do a degree by pinching off all the lines but that isn't the best way to check I know. The water pump was supposedly replaced not long ago, but that doesn't mean they were wise enough to do the belt at the same time. Will keep you posted. Thanks again.