Re: 1990 mercury topaz (Babe magnet)
Another cheap and easy thing to check is the IACV (Idle Air Control Valve). Its on the back side of the intake manifold. You need to remove 2 bolts, and a plug in connection on the bottom. Make sure you remember the gasket, if it shows signs of excess wear, replace it. AS for the IACV itself, use some break cleaner/throttle body cleaner and spray the inside until its like new. You can also move the valve up and down, while spraying it, to free up any dirt/sludge that buillt up inside. Also give the IACV a shake, you shouldn't hear anything rattling (may be a sign of a bad part). While your at it, change your air filter also, then you'll be sure to get a good flow of clean air through the motor. Hope that all helps, BTW here's the IACV circled.