Fiesta auto revving high

[mildwin]

Was driving my fiesta auto M reg, got to lights & the revs went up & down of their own accord. Pulled away & car was fine. Went into a retail park, & when got back in car it was dead. Had to call breakdown recovery & got towed home. It was the battery so has been replaced. Now starts fine but is revving high about 2500 when first turned on, when put into gear it is ok, revs drop back down. But also the gear changes on the automatic gearbox are not smooth. Any ideas much appreicated.

[shero101]

Check out the throttle position senser. This is a common problem and replacing this part normally fixes it.