88 560 sec rough idle

[tommtkw]

Hi,
I recently purchased my first Mercedes it is a 1988 560 sec. I had been looking for this car for a while and finally found one with a color combo I liked. Anyway the car has a rough idle. I had brought it to my mechcanit. He flushed the fuel injectors and said it should clear up. It has not. the car has plenty of power. It has a 111-k on her and runs and drives like A Dream,I wonder why I waited so long to buy one. If any one has any suggestions or help on this matter please let me know.
Thanks
Thomas

[jdc1244]

Hello and welcome![:)]

You need to post your question in the w126 forum, everyone there would love to see your car!

While on your way to the w126 forum, here’s some light reading to get you up to speed on M117 idle issues:

http://www.benzworld.org/forums/forums/thread-view.asp?tid=1173012&posts=7&hl=usual+suspects

[langpfeife]

Hi,

For a "rough" idle, you may want to have your mechanic check the lambda on/off ratio.
It may never have been adjusted, and my experience is that *generally* the system
tends to go toward the "lean" side over the years (e.g, high control voltage), which will
cause a rough idle. Make sure any other needed maintenance is handled before tho,
especially your fuel filter. (A dirty/plugged fuel filter will affect the on/off reading.)

Vacuum leaks around the injectors will also cause rough idling.

Beautiful car, BTW...the 560 coupes are awesome vehicles...and in good condition, I
have a feeling they will be worth a LOT of money in the next 5-10 years.