Discussion:
560 SEC Idle Adjustment Screw - Where?
(too old to reply)
CalicoCat
2005-04-05 03:16:57 UTC
Permalink
I can't find the Idle Adjustment Screw on my 1988 MBZ 560 SEC; All the
throttle bars are properly adjusted and not pulling the throttle open.
Where is the adjustment for idle speed? Thank you in advance to any
postings!
M. Davis
2005-04-05 18:27:24 UTC
Permalink
There is no adjustment for idle speed - it is controled by a small
analog computer (control unit) through an idle speed air valve. You
can adjust the mixture by way of a (iirc) 3mm hex wrench in the top of
the fuel distributor.

These affect idle speed:
- Leaks in the intake side - manifold gaskets, vacuum hoses,
diaphrams, seals, etc.
- Coolant temperature sensor
- Bad wiring, especially bad grounds
- Sticking idle control valve
- Bad news - most common problem is the expensive control unit, but
there are people who rebuild these for reasonable cost - search this
group for sources.

Diagnose first - you will run out of money before they run out of
parts. The shop manual will give you diagnostic steps. Good luck.

Mike - '82 380 SL
CalicoCat
2005-04-05 19:13:53 UTC
Permalink
Mike,

Thank you for taking the time to spell out all the great advice!

Very much appreciated,

John
Post by M. Davis
There is no adjustment for idle speed - it is controled by a small
analog computer (control unit) through an idle speed air valve. You
can adjust the mixture by way of a (iirc) 3mm hex wrench in the top of
the fuel distributor.
- Leaks in the intake side - manifold gaskets, vacuum hoses,
diaphrams, seals, etc.
- Coolant temperature sensor
- Bad wiring, especially bad grounds
- Sticking idle control valve
- Bad news - most common problem is the expensive control unit, but
there are people who rebuild these for reasonable cost - search this
group for sources.
Diagnose first - you will run out of money before they run out of
parts. The shop manual will give you diagnostic steps. Good luck.
Mike - '82 380 SL
kingking
2020-09-19 23:45:04 UTC
Permalink
When i try to adjust the ifle of my sel 560 ok for a few seconds and i stop it and start again totlly not starting pls help me thank you
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