I have a 1982 Series 3 diesel which I bought about 6 months ago. It is equipped with a hand throttle, also known as a engine speed hand control.

Having never touched it before I thought "maybe I will move the lever and see what it does." It turns out that was a bad idea.

After moving the hand throttle something happened and now the accelerator only had the slightest affect on engine speed - barely brings the engine above idle even if I floor the accelerator pedal. I looked at all the throttle linkages and everything seems to be where it is supposed to be. Moving the hand throttle back to where it was didn't do anything to change this.

When I move the hand throttle the accelerator pedal moves up and down slightly. Below is a picture of the original position of the hand throttle and where I put it back to.

Anyone have any ideas as to what is causing this?

 

Turns out that my last shop attached all the throttle cables all wrong. When I moved the handle it popped off. Also when I pressed the pedal all the way down it went past full throttle - timing was all off.

New shop fixed it and diagnosed the problem in 20 minutes and it runs much better.