4 Wheel Drive/SUVs: 2000 Honda Passport, honda passport, coolant temp

Question
My 2000 Honda passport has been making putt putt sounds when I start it in the morning, the engine revs high until i put it in anything other than park, and it goes no higher than 20 miles an hour for a mile or so before it kicks in and starts acting normal.  What can cause this?  It only does this when the car is first driven for the day - wont do it later in the day if you drive it again.

I did take it to a Honda dealership and they werent sure but thought maybe it was the fuel pump or fan clutch.  I had both replaced by someone else and the problem still exists.

Answer
well I would say that those two wouldnt have been the problem anyway , I would say it is more in the lines of a coolant temp sensor, if the computer is telling the engine it is too cold or too hot it will dump more fuel than it should, or not enough fuel, so I would mention that to your mechanic and see if he has checked that out yet, thanks ADAM