82 240d, auto. Many years ago the owner ran it on WVO, maybe 20 years. I bought it, fixed some drivability problems (trans, vacuum leaks and more to go).


Car starts great, is the smoothest idling 240 I have seen (I ahve two others) and now runs great, quiet, smooth, reasonably peppy. About to put it on the road as DD.


Took it out last week for the day, ran great until on my way home, losing power/speed eventually down to first gear at max throttle, barely running. Then it would start to clear up and accelerate before failing again about 30-40mph. Went through half a dozen cycles before I got it home, poor running for a few minutes, clearing up for a couple minutes. I did notice earlier in the day that a few times at a light the idle was normal 240 shakey, then it would be fine at the next light.


Did a diesel purge this am with both fuel filters. (BTW, the fuel was filled maybe a month ago). Not much return fuel except at higher rpms, but seemed to run OK during the purge. Then about 20 minutes into it, while running the throttle up and down it went into the fail mode and would barely idle at full throttle. Eventually stopped running, very difficult to restart. Got it running after about 10 minutes and seemed to run ok for the remaining purge (except zero return fuel now). Another failure right at the end. Reconnected lines, new filters, cranked but no start. The clear filter did fill up without priming and looks clean.


Ideas? Fuel pump? The intermittent nature presents a problem with any mechanical failure theory.