I have a 1981 264GLE (with what I think is a B28 engine, though it might be a B27 and I've never been able to determine exactly which, because different sources on the net suggest different dates, specs and VIN number codings).

My accelerator pedal was sticking just off zero point when let go slowly. A tap would get it all the way to zero. I traced the problem to the throttle lever where it pivots on a shaft running transverse through the manifold(?). It has a torsion spring on it and the idle adjustment screw is also there.

I disconnected the 'carby' link (the connecting rod that has press-on rod-ends at boths ends) that runs between that lever and the circular disk/lever that holds the cable. Hence the throttle lever was now completely free from the cable, circular lever and carby link.

With the engine off, the throttle lever was free and no matter how slowly I let it down, it always went to zero (i.e. the idle adjustment screw always hit the stop plate).

With the engine running, slowly releasing the throttle lever caused it to stop short - with the idle adj screw just under 2mm from the stop plate.

I thought it was strange that whether the car was runing made any difference (but that is a demonstration of how incomplete my knowledge of my car is).

I sprayed RP7 lube on the lever (where the torsion spring is) in the hope that it may free it up. Days later - no change.

I figured the throttle shaft must have been getting stuck inside the manifold. I didn't like the idea of venturing in that direction. I noticed that the circular disk had its own stop and that when the throttle was at zero (idle screw closed completely), the disk and carby link were actually moveable without moving the throttle. So I adjusted the 'carby' link (made it shorter) so that when the idle stop screw was bottomed out, the circular disk was only just reaching its stop point. This meant the circular disk's spring was also helping the throttle close all the way to zero.

The throttle hasn't stuck since (I made the adjustment only three days ago, but I would have expected it by now). But the accellerator cable is looser than it was (because the circular disk doesn't pull on it as far).

I'm curious what was causing the throttle lever to stick, and whether there is a better way to fix the problem.

Also, while we are in this area, can someone tell me what the brass hexagonal slotted-head screws on the top of the manifold are (next to the throttle lever)? I unscrewed one a bit (one turn) and noticed the idle changed - I put it back and didn't try any more.

Cheers,
Andrew.