I just put on a FMS 65mm tb, and now i have a high idle, when i turn the car on it turns on fine, and it idles round 1200, but when im driving let's say 60mph and i put it in neutral the idle stays around 1500 rpm, the slower im moving in neutral the lower the idle goes, is it just a simple turn of the idle screw down to fix my idle problem, or is their another underlying issue?