Does anyone know where I could locate a diagram for all vacuum hoses under the hood of a '79 450 SL?
I bought this car a few years back. Runs well and is in largely good shape. Have changed out the plugs and wires, replaced some of the vacuum hoses, minor tune up stuff, etc. The issue I can't seem to solve is the idle RPM. When warm, it idles at around 500 in gear, should be 750, and in park around 1200. I've tried adjusting the idle screw, but it doesn't seem to do anything either way. The previous owner had it maxed out tight (clockwise).
Can anyone offer up some tips to triage this issue and get the idle back in line? Seems like vacuum lines are the first place to start at this point, but if anyone has other suggestions, it would be appreciated. Thanks.