It idles rough

[jsandoval]

I have a 1969 280SL Euro. When I first start the car it will idle rough even after it warms up. But after about 15 to 20 minutes of driving the idle smooth out. I am not sure what to do to correct it. Any suggestions?

[jeffc280sl]

I would check the operation of the fuel injection pump (FIP) thermostat.  Do a search on this topic for details.

Jeff C.
1970 280SL 4-speed

[ja17]

Hello,

I agree with Jeff.  This "WRD" can be stuck or it's air filter may be plugged. Take a section of rubber hose and use it as a stethescope at the tiny air filter on the injection pump.  It should be sucking air when the engine is cold but should not be sucking air after the engine is warm.

Joe Alexander
Blacklick, Ohio