I have a 1973 MB 450 SL, I restored this vehicle to life. A Mercedes mechanic (passed on last year) placed an electronic ignition box on the car.
From the get go the car will run fine, but, during cold start the car will rev fast and slow, or up and down on start up. There are times when it does that while driving and then it stalls and will not start again. The solution was to replace the new electronic ignition box. I have done this 3 times already and I think it is not the right diagnosis. The car sits in the garage and I drive it on Sunday to church and this is a 4 miles round trip. Replacing the electronic ignition box is not so appealing any more as I think it maybe something other than that. ANY SUGGESTIONS
THANKS
David

 

Hi, I got an '71 450SL. Did you replace the electronic ignition under the left front wing? I'm not sure that I got the same model, but my one got electronic injection (I'm pretty sure you got as well). There is another electronic (large one') underneath the glove compartment. There is one single screw on this (below) and -by turning this screw (for idle) the correct way, did a great change for my car... Can't remember which way it goes, but it sound very much like that your car is getting to little fuel - does the car runs hot as well, is this also an indication it getting to few gas. I bought my repair book from Haynes.uk, - it's not optimal, but helps a lot anyway!
...Forgot to tell you that the previous owner of my car rebulit the ignition system to "normal" (for the 70-80 to be) to a standard coil and contacts. It works well, and is easy, but then I got no signal to the rew counter. I would built it back to original! If you got any spare ign. electronics... PLEASE TELL ME!