wont rev over 3000

hi got a vito traveliner have had to change the engine now cant get over 3000 revs not sure why its happend and would any one on why this happens and allm so have only cold air blowing and tepm gauge wont go work right winters comeing and dont fancy runing a round with only cold air no warm air and were would i find any manuals on a vito traveliner 2001 any help out the many thanksssss kev

I think your're in limp mode. Engine does that when it's not happy about something. I think the heater is a separate issue. You could try disconnecting the battery for 15 minutes, this used to be a way of fooling it. Have you checked all your hoses are ok? Sorry not much help. I'm on three sites and no one, on any of them has any real answers with regards to limp mode as it can be one of several unrelated things. What have you tried so far?