Pagoda SL Group

W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: pede754 on July 10, 2024, 22:22:18

Title: 250 SL Auto idle speed
Post by: pede754 on July 10, 2024, 22:22:18
Advice please on idle speed control.
My 250 Auto tended to stall when manoeuvring in forward or reverse. 
Raising the idle speed is the only way to stop it cutting out.
In park it now runs at about 1500rpm and in drive drops to 600rpm which works well with no cutting out.
This a good work around but not ideal because the transition from 1500 to 600 rpm as it drops into drive is not nice. Plus the high idle in park is not right.
Does anyone have any suggestions or a fix for this.
Many thanks if you got this far down 😀
Title: Re: 250 SL Auto idle speed
Post by: Jonny B on July 10, 2024, 23:31:24
A bit off topic, well a lot of topic but -
Great plate!
Title: Re: 250 SL Auto idle speed
Post by: ja17 on July 11, 2024, 01:13:30
Engine must be running smoothly with no missing and compression must be good before you can proceed.
Title: Re: 250 SL Auto idle speed
Post by: Peter h on July 11, 2024, 05:07:12
As Joe says, the engine must first be strong and properly adjusted. The solenoid must then work so that the speed does not drop when the gear is engaged.
This can be prevented by increasing the speed and CO2, but the gear changes will not be smooth. It will jerk a lot.
Is your lifting magnet connected and working?
Is the co2 set correctly?
Peter

Of course 1500 at idle is far too high.
It shouldn't go down that much when you put it in gear
Title: Re: 250 SL Auto idle speed
Post by: Cees Klumper on July 11, 2024, 06:10:39
Sounds like your constant speed solenoid (CSS) is not working at all or is worn out. And there may be another issue as well, causing such high rpm drop.
Title: Re: 250 SL Auto idle speed
Post by: stickandrudderman on July 11, 2024, 18:01:46

Raising the idle speed is the only way to stop it cutting out.


First question is how have you raised the idle speed?
Title: Re: 250 SL Auto idle speed
Post by: ctaylor738 on July 16, 2024, 16:03:36
The second question is, is your idle switch working?

CT