Stall when Accelerator Slightly Depressed

[alchemist]

My 1967 230SL with 280 Engine idles and drive good after cleaning work done on the venturi. It warms up nicely, however, when the accelerator was depressed few millimeters, it stalls. Sometimes at the traffic stop, I have to depress the accelerator hard to keep it going. If I depress the accelerator slightly, it dies and need to be started again. I know this may be related to adjustments but of what? The ignition is timed correctly.
Any ideas where to look and adjust?

[ja17]

Check the engine linkages!

[Peter van Es]

https://www.sl113.org/wiki/Restricted/Linkage-tour

[ctaylor738]

Be sure that there is no play in the linkage.  The throttle plate and the injection pump levers need to move exactly in sync.

Move the throttle with the bellcrank on the cross shaft and check that the throttle plate and pump levers move at the same time, without play.  You may need new ball sockets.

The situation you describe can be caused by the pump lever moving "late."

Good luck,

CT

[alchemist]

Thank you all of your response. Joe and Check are correct. When I cleaned the Vanturi, the flap position changed and the length of the throttle and pump have changed too. So, I adjusted the length of both of them and that caused the present situation. I performed the split test, when I depress the pump linkage, it stalled immediately. (I do not know if this suppose to be correct). When I depress the venturi linkage, the RPM increased slightly, then it starts to stall. I believe this correct, but not sure about the pump. I will perform the linkage tour and I hop that will fix it.

[alchemist]

I re-did the linkages torr and before I start the car, I wanted to know the status of the engine. So, I pulled spark plug #6 and found out that it is running lean. Please see pic attached, the tip is white. Is the knob behind the IP needs to be turned clockwise? If so, how many clicks? Thank you.

[ctaylor738]

The knob on the back of the pump adjusts the idle mixture.  From your description of the split linkage test, your idle mix sounds about right.  The burn on the plug looks good to me.  "Lean" is really shiny white.

You've posted a lot for free.  Isn't it about time to pony up and join the Group?

Cheers,

CT

[dirkbalter]

I find below video on the linkage / idle screw test quiet helpful.

https://www.youtube.com/watch?v=28uD3JVbQ-I