OM 617 fuel check valve?

[gmbowen]

My brother and I recently drove 1800 miles straight in his 1983 300SD. At the end of the trip, after letting the car set overnight, it wouldn't even think about starting the next morning. Not a hint of combustion. Glow plugs working, vacuum shutoff to IP not stuck on. Used starting fluid, but only combusted starting fluid, no combustion of diesel. Used hand priming pump to no avail. Finally, I cracked all the flare fittings on top of the injectors. It took some cranking before any fuel came out. Once that happened, we were able to finally start the car. Since then, this procedure has to happen if the car has been sitting for more than about 8 hours. My best guess is that fuel is draining back from the lines to the tank. Anybody know if there's a check valve on either the injection pump or somewhere in the fuel system that could be haywire? Or does anybody have any totally unrelated ideas as to what the matter could be? Thanks a bunch for any ideas.

gmbowen
1983 LandCruiser with OM617

[H2O2]

I believe your hand primer pump is the check valve on the inlet side of the injection pump, and there is also a another check valve on the outlet side where the overflow return line heads back to the fuel filter mount flange. Most likely you just need to replace the hand primer pump--very common problem.

[TonyFromWestOz]

It appears that you have air getting into the fuel system.
Do you have the new type primer pump? or the old un-screw and pump then screw-up type?
The old type frequently develop leaks, leaking diesel onto the engine mount when you use it. If this happens with your primer pump, replace it with a new one and you will have fixed your problem. Your engine mounts will be longer lasting too, depending on the frequency of use of the primer pump.
If you already have the new primer pump, then you would seem to have an air leak somewhere.
Check for diesel leaks from all fuel hoses and metal fuel lines.
Check for air entering in the prefilter while priming,


Hope this helps,
Tony

[gmbowen]

Thanks to both of you for your replies. My brother installed a new priming pump on his car today, so we'll see if it starts in the morning!

[Palangi]

I have heard this problem attributed to a bad o-ring on the bolt for the spin on filter. Somebody posted that about 30 to 60 days ago. Apparently there is an old type and new type of bolt configuration, so there can be some challenges getting the right parts for your particular car. It helps to have a good parts guy.

[gmbowen]

Priming pump didn't actually do the trick, but we'll put that o-ring on the filter bolt tomorrow, and we'll see what happens.

[Palangi]

Let us know what happens. I have this problem to a lesser degree on my 240D. It starts instantly but runs very poorly for about 15 seconds. Then I can feel it getting fuel an it runs fine. If I give it a few primer shots before starting it runs fine. If the tank is full to the brim it runs fine (fuel level is above the pump and filters). I am going to replace the 3 clear hoses and the filter bolt o-rings and all the associated copper washers.

Incidently, that reminds me, you might want to snug up the 6 fuel bolts that go through the banjo fittings on the clear lines.

[all4MB]

would be nice if people followed up on these kind of things !

[Diesel911]

Old thread!
The answer to if there is a Check Valve in the Fuel System is NO.
The only valves are in the Fuel Supply/Lift Pump.
You can buy a Fuel Supply/Lift Pump Valve Kit; see pic. There is also a small O-ring that does not come in the Kit that should be replaced.

Lift Pump, Fuel Supply Pump rebuild kit
http://www.peachparts.com/shopforum/showthread.php?p=2284880#post2284880

Lift Pump, Fuel Supply Pump about sanding the Valves has the small O-ring size
http://www.peachparts.com/shopforum/showthread.php?t=266857&highlight=lift+pump+kit

Lift Pump taken apart
http://www.peachparts.com/shopforum/showthread.php?t=249082&highlight=0009934801&page=3

Lift/FUEL SUPPLY PUMP TINY o-ring
Bosch lists now 2 440 210 002 (MB 010 997 86 48) as replacement to the original black(perbunan?). And yes,the replacement is Viton.
The 5mmØ x 1.50mmØ 'O' ring is located in a groove in this bore and prevents engine oil in the IP from being sucked into the fuel re-circulation circuit. In most cases this O-ring has either hardened and broken up or completely disappeared.
http://www.peachparts.com/shopforum/showthread.php?t=261822

Some other issues are that you can get tiny cracks in the Fuel inlet Hoses or they can just be so hard and inelastic that the do not seal no matter how much the clamps are tightened.
3-5 dollars worth of 5/16" Fuel Hose (if you have a 123, 617.*) from a regular auto part store will take care of that. The Fuel Hose is also rated for Diesel Fuel; regular Fuel Hose SAE 30R7 is the Regular Fuel Hose.