Let me start off by saying, I know this is an Escort forum but, since the Tracer is nothing more than a re-badged Escort, I figure my question is pertinent.

I am looking to buy a 1997 Mercury Tracer. The price is right, $600. My only concern is that the previous owner dropped a 1.9L in it instead of the 2.0L the car came with and now it runs a little rough. Should I be really concerned about this or, does it sound like an easy fix? What I know about the car is beside replacing the engine, the PO replaced a TPS and the IAC? I think he said, to no avail. He suggested it may be the fuel pump but, I can't see that would cause the problem he is indicating unless it is sheer coincidence. Looking forward to hearing from anybody about this.