PeachParts Mercedes-Benz Forum - View Single Post

doxland · #27 02-28-2008, 05:38 PM

Once you have verified that the lift pump is good;
Connect up an independent fuel supply with a head(gravity feed), reliably suspended with a cord from the hood so it'll be hands free, unattended.
Take what you know to be a good injector and connect it to #1 injection pump pipe,
bleed air by cranking and close up tight but injecting into free air or catch can(not installed in it's cylinder.
Have someone crank while you watch and see it the IP can push fuel through the injector. Crank with accelerator part way down.
Repeat with all the other injector cylinder pumps.
Alternatively you could remove all your injectors from their holes and connect to the injection pump and crank after bleeding while watching their performance. This will be messy but gives you a good one shot trial.

This would remove your suspicions about to much wear in the pump.

There are classic tales of Marine Diesels running on heavy fuel getting along just fine on an ocean crossing then switching over to light fuel, stopping for a reverse test, and failing to start again because of wear in the IP cylinders. All pumps had to be rebuilt before ship could proceed. The wear had occured because of the rotten fuel they burn but it's viscosity was high enough that it could be pumped, but the light fuel replacing it couldn't.

Possible too, I suppose, is Lube Oil dilution for some reason or other. Make up a simple viscosimeter and compare to new oil.