1990 r129 rough running/lack of power
hi all. I have just joined mb world having spent much time looking at previous threads relating to my issues. I have a 1990 500sl which suddenly started running like a dog. The problem is sometimes intermittent and feels like a fuel issue. Misfire on idle, misfire when under load (in drive) gets worse when you push the throttle. I have carried out the following: cleaned egr valve, replaced all plugs and leads, cleaned all contacts on every switch etc. When I bought the car a few months ago, it ran sweetly. The previous owner had the rotor arms and caps done in the last 12 months and car hasn't done much more than 3k since then. There doesn't appear to be any splits or cracks in hoses, breathers etc. I drove the car back from purchase 260 miles and have used it weekends since purchase over the last few months with no problems.
Can anyone help?