Working on a 78 450SL that runs good most of the time. Last week it stalled while driving and then would not start. After sitting for 1/2 hour it started and ran fine. The car stalled again the next day while ideling in the driveway. While it was in this condition I checked for spark at the plugs and there was none. Again after sitting it started and ran fine. I don't smell fuel like it is flooding, it is not overheating. I visually inspected the coil and ballast resistors and the blue bracket resistor is cracked in the ceramic from one end to the other, could that be the problem ?

I had Circuit City install a new radio CD player about 2 weeks ago.

This sound like an electronic ignition module problem. I havent had this experiance much with MB's but I have certainly seen it alot with older Fords. Spray water on the module to cool it down and is starts right up.

John Roncallo

Any other suggestions out there?

my 76 450 ran poorly (and stalled) when I bought it.
One issue I certainly had was a clogged fuel system - I ran a couple of bottles of Techron through the system and replaced the fuel accumulator.

I'm not sure how a vacuum leak would lead to the problem you had, except these cars are so prone to vacuum problems and that could impact the idle.

But try the Techron and take a look at your accumulator.

I have no spark at the plugs when this condition occurs. Engine cranks, won't start, let it sit and it will start and run fine for several hours or so., then quits again.

no spark says ignition system, cracked resistor looks like an obvious fault. probably breaks the connection when it gets hot.

wouldn't waste time looking anywhere else on this one

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1987 300e manual 250,000 km (sold)