Hi there,
Got a problem with my 218 SLD ('91), which seems to be getting worse. It involves surges in the revs, which at motorway speeds will see it accelerate quite markedly by about five mph. Then after a while it'll suddenly drop off and slow down again.
Then I'll pull up to a stop and the idle speed will rise and fall like the ticking of a clock between about 600 and 1,100rpm. Eventually it'll smooth out.
The problem is not there all the time, but seems to develop quite quickly on motorway journeys.
The fuel filter was replaced when this problem was in its infancy and that seemed to do the trick for a while, but now the gremlins are back with a vengeance.
I'd be grateful for any help or advice.