Author Topic: Idle Speed Change  (Read 1399 times)

lowpad

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  • USA, CT, New Preston
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Idle Speed Change
« on: April 24, 2020, 02:48:21 »
The idle speed of my normally reliable 230SL recently jumped from the usual 800 or so up to 1,300 - 1,500 (when warm).  I've also noticed that it's now slower to return to idle than normal, almost as if a spring wasn't strong enough.  Before I dive into the linkage tour (much appreciated, by the way), do these two symptoms ring any bells?  The car has an electronic ignition, so not sure is something is up there unless the timing somehow slipped.  Haven't done anything else other than usual maintenance.  Appreciate any suggestions if this is something obvious.
1966 230SL (6/66 build)
French export
4-speed manual
158 Exterior / 040 Hardtop
2001 SLK230
1996 Porsche 993
1991 Acura NSX

mrfatboy

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Re: Idle Speed Change
« Reply #1 on: April 24, 2020, 03:23:44 »
Years ago I had something similar happen. It turned out to be the broken vacuum tube from throttle body to distributor.

1969 280sl (Aug 1968 build)
Signal Red
4 Speed

ja17

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Re: Idle Speed Change
« Reply #2 on: April 24, 2020, 03:27:06 »
Yes, I also was thinking vacuum leak.
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