I recently purchased a 1984 300D Turbo diesel and it was running beautifully. Then I converted to bio diesel (changed the fuel lines) and ever since I have been having issues.
The first problem I had was the car actually stalling out while driving but I found that this was caused by a kink in the line (silly mistake). So after that things started running well again but never perfect. Basically what happens is it is really slow to get going, so it will crawl at a dangerously slow speed for about 5-10 seconds before it gets going. Very frustrating when trying to turn at an intersection or take off at the lights. This doesn't happen all the time though. It seems to be particularly bad on a low tank of gas (under about 1/2 full), on an upward hill, or after having driven at high speeds for an extended period of time. The symptoms also seem to coincide with the engine idling really roughly.
I've tried changing the fuel filters a couple of times to no avail. Diesel purge seemed to fix the problem for about a week and then it went back to the way it was.
Any feedback would be greatly appreciated.