I'm having a problem with my 1994 5.0 mustang. It has an intermittent idle problem. when I start it in the morning it runs fine until it warms up and the idle drops down to normal. once the idle comes down it surges real bad and stalls unless I keep the rpm's above 1000 rpm. I changed the plugs, wires,cap and rotor, fuel filter, coil, and oxygen sensors but the problem persists. any suggestions or advice would be a great help.