Throttle Problem

I have a 1990 Escort LX with a 1.9L auto. When you give the car some gas, it stays revving at that speed and will not come down for a while. It seems 2 act up more when the car is warmed up. Even when u first start the car it will rev moderately high and then eventually come down.
Ive only owned the car for about 2 weeks and i am not fimilar with this motor. Any help on this issue is appreciated.
Thnks in advance.

Good chance the Idle Air Control (IAC) unit is malfunctioning. It is located on the top of the intake manifold, right where the large hose connects. It is a cylinder shape, about the size of a couple D cell batteries.
Some people have had success just be removing it and cleaning it up. Try that first. If the symptoms improve, either wait to see if the results last or just replace the unit.

To a degree this is normal; especially when the car is first started. Even carbeurated vehicles idle high and richen the fuel mixture when cold. If the car never warms up, either that should be addressed first or just leave well-enough alone. Engine not warming up will only cost you gas and creature-comfort as far as I know. If engine wear is to the point that it consumes oil then fix the warm-up issue. Parts expand when heated....

Could it be the throttle plate is sticking, due to crud inside the throttle valve area? Might want to start it up from cold, and then twist the throttle to make sure it is fully shut?
But if the car has over 100,000 miles on it - the Idle Air Control valve could certainly be getting sticky. In fact, mine is beginning to get sticky with only 967,000 miles on it. Im going to unbolt it and spray Throttle Body Cleaner through it a couple of times.

967,000 miles????

Maybe you could get in the Guiness book of world records. The record for most miles was a Volvo with 879,000 miles.

Hehe... I was thinking it was one of those Diesel 18-wheeler Escorts. ;) Not as unusual to find over 1 million on those big-rigs.