I have a 1985 300SD Mercedes Diesel that can be started but dies after only 3-5 seconds.
The injector pump was checked by a Diesel Mech., I took all lines off at injectors and no fuel comes out while cranking engine. Even with only one line off and engine trying to start very little fuel comes out. I think engine pulls enough fuel into pre chamber to start up but no fuel is delivered to run engine. Something to do with fuel control rod position?
Fuel lines stay full, no air bubbles after repeated priming. Initial priming sent fuel and air through inj pump and back to tank; could hear bubbling coming from thank. Is this correct??
I am totaly stymied on this one

Have you done the normal routine (crack injector lines and crank until fuel comes out and system is bled, replace fuel filters, clean tank strainer, etc.)?

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1983 240D 3.0T 4-speed manual, now sold

1989 Subaru GL Wagon 5-speed Touring Edition

I am not sure I understand the comment in Red. All the Fuel that goes into the Prechamber goes in from the Fuel Injection Pump and through the Fuel Injector. (There is no separate cold start Injector like there is on Gas engines with a Bosch Injection System.)

I would try disconnecting the Vacuum Hose (and plugging the open Hose) from the Vacuum Shutoff and see if it runs OK like that.
If it runs OK like that I would suspect that the Vacuum Shutoff Valve that is located on your Steeringk Colum Lock (actuated when you turn your Key) is allowing Vacuum to the Shutoff.

If the above is true when you start the Engine the Vacuum is low so it gets Fuel and tries to start.
As you continue to Crank the Engine the Vacuum Pump is also pumping and the Vacuum Starts to rise. As the Vacuum Rises the defective Vacuum Shutoff Valve on the Steering Colum allows Vacuum to get to the Vacuum Shut off on the Injection Pump and cuts off the Fuel to it.

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84 300D, 82 Volvo 244Gl Diesel

It is also a good idea when you are getting no Fuel to change the Fuel Filters just to make sure that is not the issue.

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84 300D, 82 Volvo 244Gl Diesel

Even after inj pump was to the shop and gone over & re calibrated it still stalled.
Then while the wife was searching the help sites on the web she found your website and on searching the problem she found a guy who had almost the same problem back in April 2009 and Biotour had the answer for me.
It was the breather line from valve cover to air filter housing that was clogged. "Rare but can happen".
I went out and took the oil filter cap off & started up. It kept running and idled fine. Put cap back on & it shut down. I cleaned out breather line of unknown substance and all is well, Life is Good!!!
Thanks Peach Parts and Biotour....I won't forget this!

Perfect.
A good thing you did the checking yourself. I doubt if a professional Mechanic would have found the problem with out doing a lot of other stuff$$$$ first.

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84 300D, 82 Volvo 244Gl Diesel

You are so right! I have found it is wisest to check these websites where people are willing to help each other out with these types of problems but I had already taken the inj pump in to have it checked and that was $350.00 wasted, everything was fine but when I got it reinstalled I had uncontrolled revving....drove me nuts! I took inj pump back out and back to shop only to find they had missed a part when they took it apart and put it back together again...who is the professional here!?
Put it back in and it started fine but died with in seconds.
I was at my wits end, thinking about a bullet through crank case?
Then the wife found the old posting and life is good again. Can't thank you guys enough...sometimes we can't see the forest for the trees and I think that happens to garages, they look for something big and miss the smaller problems.
Thanks again for helping those who can't help themselves..

it's not as rare as you might think. it's the first thing I thought of when checking your post. the shutoff diaphram on these cars has an odd way of mounting that causes this, and these engines have a LOT of blowby on them!

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