Author Topic: 230 sl runs rich when cold  (Read 3527 times)

gagsmerc

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230 sl runs rich when cold
« on: August 26, 2012, 08:31:26 »
hello,  I have a 230 sl 1966 fuel injected engine.  My concern is that when the vehicle is started cold, there is a lot of black smoke emitted from tail pipe(when revved) and the vehicle runs rough.  As the motor runs and warms up this improves and dies down but is still quite rich (noted by eyes watering badly at tail pipe) but black smoke has died down (when revving).  I have tried to understand the relationship between cold start valve and the air intake, it seems to be injecting more fuel but no noticable increase in rpm to compensate.  I have a merc oem manual but this jumps all over the place and is very difficult to understand. 

Please help.

ctaylor738

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Re: 230 sl runs rich when cold
« Reply #1 on: August 26, 2012, 14:18:40 »
This is a common problem, and there is a large amount of information about the starting aids and how they work.  You can do a Search on "starting aids" or "cold start".

A good place to begin is this thread: http://www.sl113.org/forums/index.php?topic=5486.0.

You should also look at the Linkage Tour post "stuck" at the top of this board.  It may be that your cold start/warmup is OK, but your linkage is out of adjustment.
« Last Edit: August 26, 2012, 14:25:56 by ctaylor738 »
Chuck Taylor
1963 230SL #00133
1970 280SL #13027 (restored and sold)
1966 230SL #15274 (sold)
1970 280SL #14076 (sold)
Falls Church VA

ja17

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Re: 230 sl runs rich when cold
« Reply #2 on: August 26, 2012, 14:31:39 »
Hello,

One additional bit of information.........  check to make sure that the small air filter on the injection pump is not clogged.  If it is clogged, the engine will run very rich  when warming up.
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback