I see what you're trying to say.
Uncontrolled versus runaway....
Both scary situations, but uncontrolled you at least may save some parts.
Friend of mine had a plunger stick on his 1066 pulling tractor. He got it shut down with the air kill as it neared 6,000 rpm. Runaway was also me as I put 100 feet between me and potential disaster.

 

Tell me how your going to shut it down then? There is no way to control it at that point , hence it IS a runaway.

I saw a runaway at a tractor pull once , not sure of the cause , but it got ahold of engine oil , they got the air cut off before it got past 2000 RPM or so , does that mean it was not runaway?

 

its not runaway if the governor can still regulate the maximum engine RPM, doesn't matter if you don't have throttle control or can't shut it off.......if the governor is still acting on the engine it hasn't run away..........thats the difference.

And yes thats a runaway, even though they shut it down at 2000rpm, just saved the engine. had they not done that, it would have blow by the governed speed until it shut itself off A) run out of engine oil B) rods out the block
pulling engine oil through the turbo into the intake is the classic example of a runaway. Positive air shutoff is the only 100% way to shut that down.


I just looked it up in my books, actual definition is an "External, ungoverened fuel source"


I've been around more than 1 runaway engine.

 

A runaway or runoff can come in many different forms.........sometimes they only build 2000 rpm, however most of the time they max out the tach. In my opinion a diesel runoff is caused by a fuel source that the injector pump has no control over, blown turbo, bad blower , gas well, faulty pump or whatever.The one thing I think we a can agree on is they are scary as hell and you cant shut'em down with the key

 

Ah you're right........



I can be too thick headed sometimes.

 

Ok, under the heading of stuck throttle. I had this happen to me yesterday. First off just to get this beast into the proper light. It is a 24v w/p7100 pump. The throttle seems to have jambed at or near WOT. It happened while cruzin down the highway at about 75-80. I backed off and it just kept on going. Tapping the pedal didn't do anything but rev it more and standing on the brakes just did start to slow it down, killing the key was the ONLY way to shut it off. Boy a 3500 4x4 with out power steering and power brakes is a real handful at speed LOL. Got it off the road and found that as soon as I moved the connecting link from the throttle cable to the arm on the rear of the pump it popped back to the Idle position. Drove fine the rest of the way home. Now the question I have is, is it possible that the govenor is getting under the 100 cam plate? or is it something else. I have not done anything to the govenor, it is still stock and has the same springs it was made with as far as I know. By the way the brakes are not good enough to do much more than slow this beast down, there is not a chance of stalling the engine LOL.

Dieseltim

 

For sure.... not fun..

For those instances, I have the P.A.S. installed. Not cuz I want it, but its required by law for my work...

 

Thats why I try to only work on the bigger engines, they can snap a turbo shaft in half and they will still idle down and shut down. Neat thing about the electronics on them is if the engine starts running any faster that what desired RPM is, they will start cutting off cylinders to try and maintain that engine speed.
I was near an inline 6 detroit 2 stroke when a guy started it up and watched it have a "block failure".. it was freakin' hilarious.. That little flapper on the blower didn't slow it down at all, just jerked the seals out of the blower and started feeding her nice dirty hot engine oil. Like giving a crackhead a 50 lb. rock.
Note: Its not bearing failure or rod failure... Its failure of the block to contain that broken rod!!!!!....

 

I'm impressed it stayed together at 5700rpm. Bet it sounded good.
wonder how many times the pistons helped the valves close.

 

Just because your working on big or electronic engines does not mean you are safe. Back in 01 or 02 we had a new v-mac lll in a MR chassie, the truck had TSB for the overhead.......so when the truck came in that day, I took it to the steam bay washed off the engine,tipped the cab down and hit the key and it took off, by the time I got out and made it to the air filter it shut down. I plugged into it(v-mac lll dealer software) no codes or record of the event. Later on that day a coworker found me in the high grass behind the shop heaped up naked in the fetal position sucking my thumb saying over and over.....make it stop.......make it stop.......make it stop!!!!!!

 

With a stuck plunger in an inline pump , the goveroner no longer has control of the fuel delivery, it has nothing to do with RPM, just that the goveroner is no longer in control of the engine. That's why older 2 stroke detriots without spring loaded racks have the air shutoff on the blower.

 

Just out of curiosity, has anyone even thought about posting something to help this guy in the past page and a half? I'd definitely like to know what the cause was, as something like this would definitely pucker my butt.

 

I thought the original poster was taken care of a while back.......


I have a Detroit flapper somewhere in my garage, along with three 6-71 and 1 8v-71 blowers, a governor housing a couple transfer pumps and water pump.......

but the actual fine point of a runaway is fuel from an external source. I understand what you;re saying. but a runaway is unregulated fuel from an external source. IE not diesel from the fuel tank

I'm not saying a stuck rack at WOT isn't scary or a difficult situation, but it's not a runaway. The governor IS still in control of the engine, but its irrelevant that there is no operator input, the governor is in control of maximun & minimum engine limits. So the governor is still in control of the engine.

 

So if you fire up a Silver 92 a injector hangs and unless someone fights through the noise and smoke to get her shut down, she's gonna run till she blows........you dont consider that a run-off ?????????? Detroit does

 

if it doesn't ever exceed full fuel its not a run away. The governor is still controling the max amount of fuel delivered, no? I think so. So it hasn't run away then.

any engine can run at WOT until it runs out of diesel and not fail. max fuel is delivered at rated speed and load, during governor droop. if a rack sticks or injector hangs, it will never exceed that fuel rate. so the governor still controls max fuel. So thats not really a runaway.

Alberta teaches its HD Mechanics a runaway has to external fuel source & unregulated. So if thats different than what DDC says then what can I do.