Hey guys, so I have been in the process of swapping the engine in my '81 300D with a '79 300SD's engine. I'll try to keep this short and sweet. When I went to bench test the engine before throwing it all back in, it started right up and revved to full throttle. I did not have the throttle engaged and my IP timing was set before I received the engine so my friend had to rip the fuel lines off to get it to quit.

Fast forward to the engine being in my car, It started to rev itself up again on initial start up. I realized I didn't have the brown/blue vacuum line hooked up to the vacuum port on the back on my injection pump, so I'm hoping that thats the reason to this very terrifying problem. I really don't want my shiny new engine to throw a rod or blow up, plus I never realized how loud they can get at 5000 rpms. My neighbors weren't to happy either.

Any advice would be greatly appreciated! If I need to provide any more info Ill be happy to do so.

*Ive checked the throttle linkage 10x over

keep a block of 2x6 wood handy to block off the air supply in case of a run away. Dont use a rag!

Brown\blue vac line is for the vacuum fuel shutoff. if its is disconnected the engine should chug right along and idle/run normally. I cant say with 100% certainty if an improperly installed vac shut off valve could cause a run away on a om617. dont think so tho. it is likely caused by something else going one here.

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Current fleet
2006 E320 CDI
1992 300D - 5speed manual swapped

former members
1984 300D "Blues Mobile"

1978 300CD "El Toro"

If the Throttle Arm on the Fuel Injection Pump is not connected to the Linkages.

The Governor set up so that the Governor controls it at idle and on the High rpm end. Inbetween that there is no Governor Control.
If the Idle adjustment Screw or the Rack Dampner/Governor Idle Pin are cranked down too far the rack can be pushed beyond the Governor Idle control.

The Fuel Rack inside the IP could be stuck. Not uncommon on an Engine that has sat a long time.

Remove the Fuel Injection Pump Shutoff Valve/Servo and see if that stops the run away. Disconnecting the Vacuum from the the Fuel Injection Pump Shutoff Valve/Servo will not cause it to run away.

However, I am not sure what would happen if the the Fuel Injection Pump Shutoff Valve/Servo where the Vacuum Tube/Hose connects was plugged off.

If someone improperly installed the the Fuel Injection Pump Shutoff Valve/Servo it can cause a runaway.

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84 300D, 82 Volvo 244Gl Diesel

You are not way over filled on the dipstick?

The oil level is correct, I poured an exact amount into the engine. One thing that might cause the problem is I poured the oil into the crank case without thinking. I'm not sure if that's a big no no or that's normal. Could that have caused this sort of issue?

That's not the problem. But an improperly installed shut-off valve definitely could be.

That pretty much rules out the typical "runaway diesel" theory.

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When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl.

Fact check: om60x improperly installed vac valve will definitely cause runaway.

Not the case for om61x. Vac valve cannot cause runaway.

__________________
Current fleet
2006 E320 CDI
1992 300D - 5speed manual swapped

former members
1984 300D "Blues Mobile"

1978 300CD "El Toro"

Evidently, not everyone's "facts" are the same.

http://www.peachparts.com/shopforum/diesel-discussion/88738-run-away-240d-engine-very-scary.html

There was another much-discussed incident on this forum years ago regarding a 617 that destroyed itself following a shut-off valve replacement. But that thread has apparently been deleted.

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When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl.

That was a request for fact check not a statement of facts.

__________________
Current fleet
2006 E320 CDI
1992 300D - 5speed manual swapped

former members
1984 300D "Blues Mobile"

1978 300CD "El Toro"

Well the engine came as a complete assembly when I took delivery. I'm not entirely sure what it's history entails, but It starts very strong which is apparent. Luckily when I pull the fuel lines it does indeed shut itself off, so it's not a runaway.

I'll try to take a video of it next time I gather the nerve to turn the key. I have the injection pump from my seized engine just hanging out in my yard, and it turned on with only 4 cylinders. I'll probably take that one completely apart and swap some of the parts in the one that's installed on my new engine. Also, I'll try turning it on with the shut off valve taken out. I suppose I'll be able to shorten the list of possible reasons this is happening.