Ford Repair: 1998 made is 1999, throttle position sensor, fuel pressure regulator

Question
problem have replaced  fuel pump filter iac  mass air plugs  two coils egr all oxyeng sen two cats  the car  runs excellent sometimes when i take off wheter cold or hot will go a liitle bit but does not get any power stays slow  press acecelrator nothing  for  a few mintes  and then it will sudennly  go good does not have black smoke  engine doe  not surge have checked for leaks no bad smell do you think it is   a fuel pressure regulator which is ataached to the rail they only did it for one year   have spent  1500 dollars mechanic is stumped    help  help car only has 100000  help  

Answer
Two sensors would cause that condition. You have replaced one, the MAF.The second sensor is the throttle position sensor. At the minimum, you should remove it and the idle air control valve carefully. After removing those two sensors, along with the air intake duct work, thoroughly clean the throttle body. You do this with Air intake and throttle body cleaner a cotton rag, and elbow grease. You will be shocked at the grime removed during cleaning. The recently purchased MAF has a slim possibility of being defective as well. Your check engine light should be on, if not, change the fuel filter. Let me know any codes present. It is  free service at the majority of parts stores.