I have a 03 5.0 MPI that has no power for the first 10-15 min of the day. It takes almost 20 sec to get on plane and the WOT rpms will only get up to 3800-4000(normal is 5000). I have replaced the plugs, wires, cap, rotor, oil and fuel filter. Not sure what to check next since it runs perfect after the first few min. Even if i let it sit for several hours it still runs great. Any ideas what to check??? thanks
