Ford Fiesta Engine Idle High

I Go To Start My Car And It Automatically Rev's To 3,500 Rpm's And Does Not Idle Down. If I Put It In Gear Then It Still Idles...

Hi I Have A 1990 Fiesta Rs Turbo 1.6 When I Start From Cold Its Difficult When It Does Start It Revs Up And Down .when I Drive It Its As If...