1982 Mercedes Benz 380sl

Engine Performance problem
1982 Mercedes Benz 380sl V8 Two Wheel Drive 88000 miles

If I start the car cold, it runs fine all day, till I turn it off, if I leave it off for at lest 15min or more. It loads up and runs rough till engine gets cold again! I go from about 18mpg. To 10mpg. Could it be the fule pressure vale, located at tank?
May 27, 2009.

I have forwarded your question to our M/B tech. He will be with you shortly, thank you for your patience

May 29, 2009.
It is possible. You will need to install a manual fuel pressure gauge to see where it is at. It could be a sticky injector or coolant sensor as well. Try pulling the plugs to see if any one is darker than the others

Jun 12, 2009.
Jack is on the right track. Definately check your plug condition first. If they are black you may have a leaky injector. This will cause excess fuel to be in the combustion chamber especially when hot, causing a rough running condition after the vehicle has been warmed up and parked. This model is known to have issues with leaky injectors as the car ages

Jun 12, 2009.