idle problem solved

[n/a]

I recently had a problem with my car stalling prior to warm up. Then, I began to notice that, intermittently, the car would idle too fast after warm up.  If quickly tapped the accelerator pedal while idling, the idle would drop to its normal level.

I was sure that the problem had to be related to warm up device, so I was focused on idle mixture at the FI pump.

Then, George Davis mentioned about the throttle dashpot, which (I did not know what this was, but), inadvertently, got me focusing on the venturi.  Then, I discovered that the venturi throttle plate seemed to be sticking just a little and not returning to proper idle.

So, I cleaned away some crud around the stop screw, sprayed WD40 all around the linkage to clean everything and........wow!  The car now idles perfectly!  Sometimes, it's an easy fix.  Yea, I know......not very often.

Hey, thanks George.  This group comes through every time!

Best regards,
Don
Cleveland

[Cees Klumper]

You might want to check the venturi a bit more closely sometime. It is supposed to close to the point of *almost*, not quite, binding. Many times the stop screw, with the counterlocking nut, is mistaken for the idle air adjustment and the venturi flap is set too far open.

Also, make sure all the ball joint connections are in good shape, with minimal play, and are properly greased. I spent some time on getting the linkages, gas pedal, return springs etc very clean and smooth, and this helps a lot with getting the air/fuel mixture etc set up just right.

Cees Klumper in Amsterdam
'69 white 280 SL automatic

[George Davis]

Don, you're welcome for this and the ATF suggestion - although I think you really get the credit for figuring out the venturi problem!  I'm glad it was an easy fix.

George Davis
'69 280 SL Euro manual