I have a 1994 ford escort that doesn't run smoothly at low rpm. The engine seems to cut out at low rpm. As I rev the motor it smooths out and runs fine. Any ideas what the problem is? I have changed the plugs, wires, and mass air sensor with no luck. I was told by one mechanic that it was a valve seat issue something to do with the vave keeper falling out and destroying the engine. If this is the issue, is there any way of checking without removing the cylinder head.