Engine Performance problem
1993 Ford Taurus 6 cyl Front Wheel Drive Automatic 240000 miles
Have 1993 Taurus wagon with a 3.0 v6 with 240,000 miles. The engine starts but kicks, bucks, and stalls and will not idle when cold. It runs smooth at over 2500 rpm when cold but idles so rough the car is not drivable until it is warmed up. When the car is thoroughly warmed up (about 15 minutes) it idles and runs great. The bad idle had been diagnosed in a local shop as a bad head gasket or cracked head as there was supposedly water in the #4 cylinder. We replaced the head gaskets and crack checked the heads but neither was the problem. We also replaced the thermostat and the idle air control valve. Engine still has the bad cold idle. Are there temperature sensors that could be bad?