Strange Throttle Problem
 

Recently, when I depress the gas pedal, there's a 50/50 chance that I will actually increase the speed of the engine :(

It seems like the gas pedal is getting caught on something, but I haven't been able to detect what it is exactly. A few days ago I took my car to a Benz specialist - he took a quick look at it and assumed that there was a problem with the EGR. He took it apart, and replaced a screw that was missing. However, my problem is still not solved. I have traced the throttle control from the floor of the cabin to the engine, but I'm not able to reproduce the problem unless I'm driving.

It is a 1982 240D with a 4-speed manual transmission. Normally this wouldn't be a big deal, but pulling out in front of oncoming traffic is quite dangerous when you're not sure if your gas pedal is going to work properly.

Anyone ever had problems with this?

This is a shot in the dark, since my experience is not with an MB - and not even a diesel! The symptom would be intermittant, but most likely and severe after a long deceleration.

On my Acura Integra (180k+), I have twice had to disassemble and clean the throttle body because the throttle butterfly valve sticks. This is due to build-up of a sort of varnish, which puzzles me, since little fuel vapor should be present here. It DOES completely cure the problem for quite a long while.

Steve

Try cleaning and lubricating all of the ball sockets in the throttle linkage, see if that helps. This is one maintenance step that is often overlooked.

Cheech, I had a similar problem with my 1982 300D. It was the accelerator pivot mount. When I would step on the accelerator it was like there was a rubber band in the linkage.

Yes, it does seem that way. Sometimes the pedal will not move at all... other times it will move with lots of tension, but will not affect the engine speed.

Thanks for all the answers. I will try them out this weekend!