I drive an '83 240d that I swapped a 300d turbo out of an '82. The doner car had lovecraft and he was using veggie. The car at this present time has the ALDA removed, plenty of pep in lower gears(oddly no smoke, which worries me) but will not go above 90mph period. I can get to 90, back off the pedal and the car will maintain the speed (don't do this for too long as I get a shake that I believe is cause by a bad ball joint) but when I floor it, I hear the turbo spooling significantly more but the speed does not change. The 240 was able to reach 80-85mph so I know the tank filter is fine. I removed the lovecraft, changed the fuel filters, the clear one and the cartridge, and I put in some Lucas injector cleaner in one tank of gas, sea foam in another, and now diesel Kleen in my current tank. The car used to only reach 85, now I can hit 90-92. Speedo is calibrated properly (tested with a gps). Also, I work about 25 miles from home mostly highway, if I keep my speed under 75 the car is happy, anything over for more than 5 minutes and the temp goes from 80-85 to 95-100. Once it gets there it stays and doesn't go up but it doesn't seem right. Any ideas?