[thewesman]

My 91 T-bird, 5.0 (not the super coupe) runs terrible til it warms up. The first 5-10 it is running it hesitates and jerks and worst of all stalls in the most inconvenient places. I have had everything done to it including, tune-up, fuel system cleaned, fuel filter replaced...spark plug wires changed, the diagnogstic machines show nothing!!! could it be my thermostat or maybe some sort of oxygen sensor, please help this has been going on for months!!! by the way, the cooler the temp the worse it runs. thanks