I have a '92 300D with the 2.5 turbo diesel. Has a ton of miles(240,000) but runs great, looks good, handles very European, and gets 32 mpg with 40 degree air blowing in my face! I just changed the transmission fluid it it was red and clear just like it had been put in yesterday. These are the best diesels in my opinion. Because there is a computer involved yours sounds like it may be a air-flow sensor or related problem. The computer needs to know when you have your foot to the floor and it tells by air-flow or throttle position? sensor. I paid 7500.00 for mine 3 years ago with all the work documented by local MB dealer. Ernie in Louisville