i bought a 1993 300sd turbo diesel yesterday and if you first start it and take off it will do 0-60 in 13.6 seconds (runs very well). then you stop at the next stop sign and 0-60 in 24 seconds(accelerates very slowly, no power). and it will stay like that for as long as you drive it. so i parked it for about 30 min. and the same thing when i first take off runs excellent then after a few minutes falls on its face the rest of the time. i bought it at an auction so i have no clue on anything about the car. it has 234,000 miles. today i picked up all new fuel, air, and oil filters to change. is there anything else i should change or check?