Outer Limits 4x4 Board

My 1990 Pajero is at a constant 2500-3000 rpm. what should i be checking?

For starters, I would check that there is some slack in the throttle cable. Then, I would check that there is nothing jamming the main throttle butterfly valve open. If all these are OK, I would check for air leaks in the many hoses tapping off the inlet manifold.

What motor have you got?? I had a similiar issue on my 91 NH 3.0 V6 Auto i had. Wouldn't go under 2500rpm on idle too, found problem to be idle control valve, got second hand replacement from wreckers, fixed issue and stopped doing it..