BenzWorld Junior Member
Date registered: Jul 2013
Vehicle: 1988 SL 560, 2002 M3 cab, 2007 MDX, 2011 R8 5.2, 2012 GS450 AWD
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Quoted: 1 Post(s)
88' 560SL rough idle question
Purchased an 88' 560SL in June 129,400 miles and notice it did not idle well when engine was warm. Not sure how long the car had been sitting prior to purchase (old gas?). I had it tuned-up including plugs, all fluids and filters replaced. Put injector cleaner in tank. Had vacuum hoses replaced. I have driven it about 200 miles and the rough idle now comes and goes. Sometimes it idles like a kitten while other times (5 min later) like an old tractor. It has even died a time or two when trying to leave a red light and then is a little hard to start. Once underway it runs great. My diagnosis is a partially clogged injector(s) which clear and then gets reclogged again and should improve over time and with additional injector cleaner. My mechanic says it may be a vacuum leak at the intake manifold, and he also mentioned fuel pump relay, but why would these causes be intermittent? Are there anyother thoughts? Is this a common issue in these cars?
Also yesterday out of no where the tachometer stoped working for about 5 min and then started back fine. This is the first time this has happened???