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Rough idle and poor performance

1K views 11 replies 5 participants last post by  wooky_chew_bacca 
#1 ·
Thanks for having me in this forum, I am brand new to the Mercedes brand, have a 1986 W126, 99,000 original miles and the car has a rough idle, and sputters during acceleration off idle and cleans up around 1800 rpm.
The fuel pressure regulator was leaking, and I have replaced that.
Looking to see what I can do myself. I am a motorcycle tech, and can work on many different types of cars, but never tackled this mechanical injection system that is on this girl, so any help would be appreciated.

Thanks
 
#2 ·
Welcome, KennyV.

Lots of info here about the CIS-e system. Lots of good info in the factory manuals, too. I'd start with tune up and getting the correct, non-resistor plugs in there: W9DC or DC0 for the 560s.

What model did you get? Any pics?
 
#7 ·
Welcome To The Machine Kenny, you think you're gonna get away with just ONE picture :grin OH NO you won't :wink

The parts stores stock resistor plugs because most engines take them, OH the counter guy will tell you "they fit and that's what the computer says goes in your car". Yeah, they WILL "fit" (screw into the hole) but they aren't the correct plug. I went round and round with them on a set for the SE, plugs ordered and the wrong ones sent, I ended up getting those from a forklift supply outfit (no I can't remember their name)

Anyway, again Welcome, LOTS of info and good folks here and we'll be patiently waiting for more pics (car porn :devil)
 
#8 ·
you will enjoy the car, just change the plugs and you can get them at Fletcher Jones. Also, a fantastic gentleman local to you is Mike Ramay. Hit him up, there may be several tidbits of info he can help with. He has forgotten more than most have learned regarding the W126. Welcome, and perhaps a generation II is in your future...
 
#9 ·
Being a master tech, Ill figure things out, I went through the spark plug thing with old Mopars as well. Parts houses just couldnt understand why the resistor plugs didnt work, lack of training is part of it.
Goal is to add a AMG ground effects kit to this car as well, might even go custom on the color, not sure yet. Going to get it running right first, learn about this fuel injection system, then maybe even add a turbo down the line.

Drives great.
 
#10 ·
Also - forget all the crap and gap them to .040-.042 without question.
 
#12 ·
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