steveemann

hi members i have just recently bought an old mercedes hymer camper and its got a 240 diesel engine it seems to run well but on idle it revs up and down ?after about 2 thousand revs seems ok have looked at throttle linkage and one rod goes to back of diesel pump and another looks to go to inlet manifold if i disconect the one of the pump it seems to level out but revs higher feels like play wear in the one on pump can anyone help me please steve