ive just rebuilt my 99 gtp with forged internals i fired it up today and once it warmed up if i reved it up to around 2000rpm it will have a slight miss or hesitation to it and then it revs up only when its warmed up if its cold it wont do it its got msd wires and coil packs as well as new plugs all new vacum lines as well theres no codes coming up and no smoke out the exhaust im lost as to what it could be any help is greatly appreciated!!!