'92 300SE. 135k miles.

On occasion, the throttle on my car will "self actuate" (I think).

Here's the scenario. In many neighborhoods here in Houston, speed control "moguls" have been installed. Different than a speed bump, they're about 6" tall and 4-5 feet wide, crossing the road from curb to curb. More of a gentle "swell" in the road surface.

Intended to slow idiots that don't know you're supposed to drive slowly down residental streets.

Prior to this problem, I could easily take these bumps at 15-20mph. Now, at that speed, as the front tires cross the trailing edge of the hump, and I get the suspension compression that occurs as the nose dives down after crossing the crest, I feel a surge in the throttle and a "click" in the pedal under my right foot.

The surge is very minor, but it is definitely there. It never persists more than a fraction of a second.

It also occurs if I hit extended rough surface roads. There's a point on my daily travel to work where the road is under construction, and a trench was cut across the road about 4-5 feet wide, then refilled and temporarily patched with asphalt, which is now pock-marked with holes and undulations. Nothing that would require one to reduce speed - hit it at 35mph this AM and felt the same issue underfoot.

I've checked the throttle cable that goes from the accelerator pedal to the linkage at the front of the intake manifold and have come up with nothing. Everything looks fine and is tight. Manual operation (key off) of the linkage shows free movement - no binding.

Engine mounts are fairly new (<15k) old.

I've not checked trouble codes. That is my next step.

Any ideas or suggestions?