Sluggish acceleration from stop until it reaches 2000rpm

[rwh]

I have a 1964 230sl #5423. It has recently exhibited a problem where when I accelerate from a stop in first gear it moves very very slowly - no power even if I put the pedal to the floor.  When the engine reaches 2000 rpm the car then takes off -- lots of power and acceleration.  I had the distributor rebuilt (Glenn Ring) last summer and all seemed well then.  I have experienced some fuel pump issues where fuse #8 will blow when doing slow driving around town -- still need to get the fuel pump and tank condition inspected.  But any ideas as to why it moves very slowly below 2000 rpm?

Thanks.

RH

[Tyler S]

Do you have a vacuum advance or retard distributor? If you have a vacuum advance distributor, make sure the vacuum lines to the throttle body and advance diaphragm have not come off. Also check that the diaphragm is not blown. What could be happening is if the advance diaphragm is not working, you will get no advance at lower RPM until the mechanical advance takes over above 2000 RPM. Check these first.

[rwh]

I have a vacuum advance distributor, an "046". I checked the vacuum hose before I posted and both ends are connected where they should be. I will test the actual vacuum and respond.

[rwh]

I took the car to an independent shop in the area and they tested the vacuum.  It was leaking at both the distributor and the throttle plate.  He replaced the threaded insert at the diaphragm and a fitting at the throttle plate and all seems to be fine now except that there seems to be some "stickiness" in the throttle linkage.  That is, the accelerator doesn't have a smooth, gradual feel -- it seems to bind early on and then move more freely. I will now need to check the linkage rod lubrication.

RH

[Tyler S]

If the mechanic has the throttle plate stop screw adjusted too far in, it will cause the plate to bind in the bore. It may need to be re-adjusted after the work that was done. Try your lubrication idea first then follow the linkage tour to adjust the throttle plate stop.

[ja17]

I agree with Tyler! Adjust the stop screw.