sounds like your ecu? i had a similar problem my car would rev up to 3000rpm as i started it then drop back. What you need to do is reset your ecu. Disconnect negative lead of battery, press brake pedal for 10secs to remove any stored capacitance in circuits, now reconnect battery put handbrake on, start car without touching accel pedal, then move gear into drive without touching any pedals, leave in drive for 10mins, ecu adaptive strategy is now set and turn car off. start car and it should be fine.
1997 EL Ford Fairmont.
1 Owner vehicle,
78000km's on the clock (12-1-05),
Showroom condition with all the fairmont goodies,