has anyone ever had a run away motor and or does anyone know the symtoms of a runaway motor and can you stop it. I am getting really woried that the motor i JUST bought is headed tht way and i dont want it to.

 

2 ways to stop it. cut off the fuel, or the air.

i had a mack truck run away when the injector pump drive broke and we could not get to the air intake safely, or pull the fuel line. it ran at 3200+rpm for around 5 minutes before it finally seized up...

 

not pretty! mikey, just how far is yours going on you? for awhile mine would run like hell for 1/4" of pedal, i once let it run to 85 at that pedal position just to see what it would do before i'd had enough. the cause was the cold advance solenoid recieving power when it shouldn't. still haven't diagnosed the root cause, but leaving it unplugged is working for now.
does yours still turn off for the key?

 

Like Tom said, IP failure is usually the cause. In some cases, a major failure of the turbo shaft oil seal can pump motor oil into your intake causing the motor to "drink its own blood" til there's no more left.

 

well see the only thing that my motor is doing that is causing me to believe that it is headed for a "run away" is that when im driving it not so much as when it starts up or idles but when im driving it is when i go to shift it likes to slowly come down from the rpm that it was at. and by slowly i mean slowly it generally jumps when i get it in the next gear the rpm is still that high but its not maxing it self out it just likes to sit there and if it were the cold start that would be the one with the yellow cable to it right that also has the high idle soloinoid correct

 

that sounds like your throttle cable is getting sticky.

the cold advance solenoid is the rear of the 2 connections on the top of the pump, i don't think its what you're having an issue with

 

As stated the only way with a diesel is to shut off the air or fuel. Sometimes you can put it against an immovable object and stall it, but that only works with a manual, and sometimes not even then, it might just spin the wheels.

If you have a turbo failure the only option is to shut off the air as the sump oil is the fuel. It doesn't have to be a major turbo failure. Something as "simple" as a restricted turbo oil return line could cause it. If it's burning the motor oil as fuel an injection pump governor won't have any effect in limiting the revs, only the amount of air it can suck in will.

Usually an engine will self destruct if you can't stop it.

An air shutoff in your air intake will let you shut off the air as soon as you realize you have a run away situation. AMOT-Products-Butterfly Valves
There are probably other companies that sell them as well.

All that said, I agree it sounds more like a throttle issue.

 

okay well if it were a throttle cable issue does anyone have the throttle cable part # so that i could look that up and i dont think its burning oil it does it every now and again really doesnt do it all the time and also it gets touchy as in threw a day for every time i start it it would be just about every other time that i start it, it acts like it has a turbo behind it and the next time i start it, acts like its N/A so im just getting curious to the fact that it might have a fuel issue also but im not sure on that

 

easiest way to test the cable is to rev it in neutral. if it slowly revs down, go out and disconnect the cable from the injector pump and rev it at the pump. if it idles rite down, it is the cable.

 

or you could just pull the arm on the pump back and see how long it takes for it to come back to rest with out the engine running

 

A good trick is to keep a CO2 fire extinguisher handy, if the engine starts taking off then shoot the CO2 into the intake until the engine stops. This gets rid of the oxygen needed to run, but if you stop before the engine dies completely it'll take back off. Don't try it with a chemical one.

 

Dodge running away after pull - YouTube This one blew a oil seal on turbo worst case scenario burning the motor oil it needs to lubricate the parts turning 3,000rpm haha

 

I have a 6637 air filter on my cummins so i just carry a nice heavy duty plastic bag. This is my solution if something should happen i just go under hood slide bag over filter and it sucks onto filter causing no air so it shuts down. This way will resilt in a crushed up filter though. I used it once already to prove to my idiot buddy it would work he was mad about his air filter afterwards though.

 

detroit 4-71 in gmc 650 running away start after the 30 years - YouTube

this one ran away, well because thats what detroits were made to do LOL

 

John that video has always made me laugh those younger guys run scared as all get out haha. If that older fellow was not there it woulda been blown up for shure.