throttle positioning
 

hy guys, i will apreciate if you can help me. I got my mercedes to mechanic and the computer show a problem, it's call " close throttle position". in the city it's driving ok, but if i will drive on interstate, after an hour of driving, when i will push the pedal all of the sudent, my acceleration disapear, it stay at 5000 RPM, and it's kicking in only wen i get to the kick poin. I got to stop and turn off the engine, and then start againe, and it will go perfect.
Any ideeas? thank you.
P.S. sorry for my english
P.P.S. i got a '95 E420

What was the code?? #224 or something else??

yes, this is the code (or it may be 24 only)i will look againe

yes, its #224

no ideea? somebody?