newer diesels run away becuase an injection pump breaks in a certain way to allow unrestricted fuel.
OR
remembering that diesels run on about anything, including oil… a turbo fails allowing oil from inside the turbo cartridge into the compressor side of the turbo. The engine WILL run on its own oil until the oil supply is cut off. In a diesel there is no throttle plate like a gas car, rpm and power are controlled by the fuel and the fuel only. unlimited fuel such as oil pissing into the intake plumbing from a blown turbo = unlimited rpm.
Detroits are completely different in the way fuel is controlled and can fail in other ways that I dont think anyone here cares about so I’m not going to bother typing. But the above mentioned scenario applies to any and all diesel engines, including detroits…
Yeah Detroits can run away fairly easy when babies or body parts are sucked into the massive turbo. Those motors feed on flesh and blood, ask your grandpa.
the new DD’s are still good engines, good fuel economy and last longer than junk CATs or cumstains due to a significant amount of less internal moving parts
weve never had major problems with them besides a few recalls i just think yhere to clustered now all the emissions shit and the d.e.f systems and weve done quite a few starters on them and there only 2 years old i want to see how they hold up in the long run
in places like california they are starting to mandate and force out the older trucks. You can get some old screamers out there for less mid 90s accord prices. Nice trucks too.
Detroits injectors run off the same cam as the 4 exhaust vales per cylinder, IIRC (2 stroke diesel, Air enters the ports in the bottom of the cylinders that is aspirated by the necessary blower). So you can imagine how a valve train issue may lead to a run away
Well in actuality the cam only “fires” the injectors. The fuel is actually controlled by a mechanism called a control rack which has fingers that move plungers in and out of each injector. When a detroit is shut down the rack defaults to the full fuel position to aid in starting. The problem comes in when the engine sits for a long period of time. The plungers get stuck in the injector bodies and it sticks the rack at full fuel. In the late 70s detroit updated the design to use spring loaded fingers so that one stuck injector wont stick the entire rack and help prevent run away. With this design update detroit did away with the emergency shutdown flap located on the inlet side of the blower.