Missing? and fuel problem

My 1989 toyota corolla has a miss in it when starting and at low rpm and at high rpm is fine

You probably have one plug not firing. First, check all your plug wires to make sure the boot is pushed on all the way. If there is no improvement, you can pull one plug wire off at a time (with the engine running). If the engine doesn't die, or change when you pull a plug wire off, that will be your bad plug. It should change drastically when you pull a wire. Be sure to use a spark plug wire puller, or a heavy rubber glove. Check for spark in all your wires with a timing light.
If there aren't any dead plugs or wires, the next thing to check is the timing. Aim a timing light at the timing mark on the crank. If the mark jumps around a lot, the timing belt or chain has jumped, and will need to be replaced.
If that checks out okay, the next thing to do is a compression test. You may have bad valve.