Folks;
My 560 SL will not run properly on hot starts. It starts fine, but idles at very low speed ~450 RPM and will not develop enought power to run the car when put into gear. Also,the car has never idled above about 600 RPM; there is no "high idle" even on a dead cold start.
Throttle position switch and idle speed controller have been replaced. The idle speed control valve seems to be OK since the idle will speed up to about 1500 RPM when the electrical connector is disconnected.
Does anyone have any experience with this that may be able to help me.
Thanks

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James L. Lloyd
1988 560 SL

I'd bet on the idle speed control valve. If it is sticky, the conrol unit will pull more amperage and lower the idle until the control unit hits its limit (usually at about 1 amp). Sounds weird, but I have never seen a faulty control unit that did not have a bad idle control valve.

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Benzmac:
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Benzmac
Thanks for your response about my idle problems. Could you elaborate a bit on how the idle control valve can be sticking since when I disconnect the connector the idle goes right up to about 1500 RPM? Do you mean that at intermediate currents (between 0 and max) that it sticks while moving?
Thanks,

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James L. Lloyd
1988 560 SL