Are my diesel injectors knackered?

[tinkicker0]

Easier said than done, diesel engine overrevving in self destruct mode, smoke, fumes, been there and seen it, braver men than I ran to a safe distance and waited for the bang. Con rod through the block, all main bearings and big end shells vaporised, valve gear dropped into cylinders.

Best advice, stay clear till the engine stops. then start clearing up the mess !!!

Top advice.

Seen an AEC 760 get off on lube after gasket failure allowed oil to be sucked from the pushrod cover into the manifold and also a Ford 1800 TD in a P100 pickup truck runaway due to turbo bearing failure. I happened to be driving it at the time. Forget stalling it. Stop at side of road, run up the banking and watch proceedings from a safe distance.

In both cases you would not be able to see the engine through the smoke, never mind find the air filter.
A leg full of glowing hot metal fragments ejected from the side of the block at considerable velocity would not go down well either.

Once stopped a Gardner 6LX Horizontal with a stuck rack by holding a clipboard over the intake and got a right rollocking off my gaffer for it. Do it again and I'll kick your backside was the words he actually chose and that one was governed, not a runaway.

 

[Ludd]

De-compressors ?

Blocking the air intake ? (don't use your hand)

CO2 fire extinguisher up the air intake ? (don't use powder !)

Decompressors are not found on many engines these days.
The fire extinguisher might work.
Blocking the air intake DOESN'T,strangely enough.
my md21a pump jammed wide open,so diesel only,but only way to stop it was break the fuel line.
Bloody alarming when it happens,but fortunately no damage.
Cuse appears to have been contaminated fuel.

 

[tinkicker0]

Blocking the air intake DOESN'T,strangely enough.

Depends how good your piston rings, valve guides / seats / seals and intake sealing are, also on camshaft profile.

A diesel will get air wherever it can, even from the exhaust manifold.