I assume that this was happening before you replaced all those components. I wouldn't be surprised if one of the components that you replaced was defective or a gasket not seated properly. Seen it here before. Or one of the vacuum lines that you replaced is leaking.
Do a search of the forums for "vacuum leaks". A method to determine if you have one is to spray a small amount of throttlebody cleaner in and around your intake and vacuum lines. If the engine stumbles or you can visually see the spray being pulled into a vacuum line or gasket, then you have found the source of a leak.
Another method would be to spray ether, as A-Train suggests. The engine would not stumble, but would gain rpms.
I am not familiar with what can fail in a MAP, other than it helps the EEC control the EGR vacuum, timing, and fuel.
Don't give up, after replacing what you have, it will likely be something relatively easy to correct.