Insure you are doing the drip test correctly, since it is easy to screw up and mis-interpret the data. You are looking for the cut-off point where the IP port first closes since that marks "start of pressurizing". Before that point, you can pump the hand pump and fuel will flow/squirt out the delivery valve port (w/ guts removed). When the port closes, you won't get any flow. It is a very sharp transistion. I don't even bother with the manual's "special drip tube" and such. It goes from squirting to nothing in ~1 crank degree (which you can barely set w/ a wrench anyway). If you want to count drops, do that too. If you have a 1984-85 engine, with rack sensor on the IP, you will find getting at one of the 3 nuts very challenging.

I set my 2 300D's to 27 deg, instead of the manual's 24 deg, since many say that can give better mileage and performance, at the expense of louder idle. I didn't notice any difference in idle noise. Seems my mileage has improved, but I rarely take long trips for a good apples-apples comparison.

he has M style pump (I never saw sensor on M)...much much easier to replace than MW. (no oil filter removal at all)

.

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w126 500SEC gen II euro, powered by OM617 turbo stolen from 84 300SD 2.88 diff,EGR blinded
next wish/project: w114 coupe OM603 powered

Before I find out the tool I was about to order is for some reason not quite right for locking my '83 300SD pump (they call out "300D" but not "300SD") - can anyone verify? They cite "OEM 601 589 0521 00" which has a lot more digits than the one that Diesel911 mentioned here and there (601-521). Looks identical: Laser 5974 Bosch In-Line Diesel Fuel Pump Timing Pin for M B 601 589 0521 00 | eBay

I intend to pull my pump only long enough to replace the gasket with something reasonably durable - minutes, that is. The only other IP I've had out (on an unrelated engine) tended to 'spring itself' to the next low point on the IP's cam, so in that case, without being able to put my eyes on the timing marks on the gears (that requires removal of the large timing-cover), I would not be able to simply be careful not to rotate the driven gear, change a gasket, and then slide it back into place, since it would spring itself to some new orientation. Does this pump exhibit the same behavior? Or is it possible to pull it out in any position, change the gasket, and slip it back in the same position? Or just use the "in-a-pinch" method with a lug bolt to lock it in that orientation? (Does tightening a substitute bolt in that position potentially damage something if the IP isn't rotated to the right orientation?)

I haven't been able to find a wiki or complete guide for this process - anyone?

--Dave

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'83 300SD - daily driver
'97 Dodge Cummins
'60 & '64 Minis
...etc...