I have a 1986 560 sel that until last week was running and driving fine. The first sign of something going wrong was a rough idle that would come and go. Also when the rough idle was present, there was some hesitation on accelerating from a stop. THen one day I stopped at a gas station, filled up the car, and when I went to start it up, it would'nt start. I checked for spark and fuel and found that I had great spark, and fuel going to the fuel distibutor, but the car would only run briefly, if carb cleaner was squirted int the intake.. almost as if the fuel distributor was not allowing fuel into the injectors. After about 20 minutes, it strarted up and has not failed to start since. I have also noticed that my passing gear has stopped working. The car starts smoothly when cold, but the rough idle now appears when the car warms up. Also, the car does not seem to have the power it once had.

I have prior to all of this, as of a few months ago, changed the coolant temp sensor, all intake manifold gaskets, (including the doughnut rings )eha valve, spark plugs, fuel distributor (which came off a low mileage excellent running wrecked car), fuel filter, pressure regulator, idle speed relay. Cap and rotor and wires were also replaced prior to these problems. The car has 140k miiles on it. and prior to all of this, ran like the proverbial bat out of hell... Anyone have any ideas? Any and all help greatly appreciated

Sounds like you could have a problem with the electrics feeding the fuel pump or the fuel pump itself could be failing.

Check the Fuel pump relay and the OVP relay, they are often points of concern.

Kickdown is actually connected to the fuel pump relay, so thats probably a good indication of your problem.

I was planning on replacing that fuel pump relay soon anyway, as I have seen them work fine one day, and then fail the next on these old cars. I'll give it a try and post a reply.

this sounds like the warning that the flywheel pickup gives as it is about to fail.it goes from trans bellhousing on upper left side to ignition unit on inner fender behind left h/light.if the wire is green it's an original the replacements are black.

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David S Poole
European Performance
Dallas, TX
4696880422

"Fortune favors the prepared mind"
1987 Mercedes Benz 420SEL
1988 Mercedes Benz 300TE (With new evaporator)
2000 Mercedes Benz C280
http://www.w108.org/gallery/albums/A...1159.thumb.jpg

What does this "flywheel pickup" do? Does it have anything to do with the rough idle?

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Current cars:
2000 ML55 AMG, 174k miles
2003 C240 T-Modell, 202k miles
1995 S320, 207k Miles