I have an 88 190E 2.6 and sometimes when I'm driving, i'll step on the gas pedal and the economy gauge goes up so i know it's using gas, but the car will bearly accelerate even when i'm almost flooring it. Then when I floor it, it drops down a gear and then it will go. The RPM's stay the same before it drops down a gear so that means it's not going into neautral because if it was then the RPMS would go up. So does anybody have any clue about what could be happening?