Any idea what the issue is here. Just replaced the injectors nozzles with bosios after having them rebuilt and balanced. Reamed and replaced glow plugs so starts up cold (cold is 45 here in Socal) after glow plug light goes off great. After run for a bit and shut down though won't start until I wait for a mysterious hiss sound, if I try to star before hiss it just cranks and cranks even when given pedal...

I'm guessing it's a problem with the vacuum to the fuel shutoff. Does the hiss sound like it's coming from the ignition switch?

Agree with Craig. Pull the brown vacuum line off the shut off diaphragm on the back of the IP and I bet it starts right up.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Okay....but kerry. What part is defective? How is the vacuum suppose to get released to allow the shut off diaphragm to return to it's "start engine" position.

I think I have a similiar issue. After pulling the vacuum line off the top of the VCV, the car will start right up.

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daw_two
Germantown, TN

Links:
Sold last car --- 05/2012 1984 300D Light Ivory, Red interior
No longer selling Cluster Needles Paint
No longer selling New Old Stock (NOS) parts

Past:
3/2008 1986 300SDL "Coda"
04/2010 1965 190D(c) "Ben"
& many more

There is a vacuum switch built into the ignition switch assembly, it's possible that it's failing to remove vacuum from the shut off.

Sounds like your vacuum switch at the ignition is bad, not releasing the vacuum until it all just leaks out. They're about 25 bucks new.

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1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg

See photo:

http://catalog.peachparts.com/ShopByVehicle.epc?q=&yearid=1980%40%401980&makeid=63%40%40MERCEDES+BENZ%40%40X&modelid=6229%3AMBC%7C2515%3AED%7C10000132%40%40300TD&keyword=ignition&subcatid=P:241652@@Ignition+Lock+Assembly&mode=PA

yeah, bet it is the ignition vacuum valve/SOV as the car just started to take about 2 seconds to shut down when it used to shut off immediately when you turn the key. Hope this is easy to get at from under the dash, or do I need to remove the key tumblers and all??

You can test it in two ways. You can use the STOP lever, and then see if the car starts right up again. Or unplug the vac line to the shut off valve right after you shut the car down. Then try starting again. The valve on the ignition switch is a pain to get to, you'll have to remove the instrument cluster to get to it. It's pretty tight to get to.

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