Fuel in Return Hose is Black

[River Cruiser]

Is this a turbo charged perkins? I saw a Mack engine runaway once because of a worn turbo passing oil into the cylinders. Good luck

[undercutter]

Zee,

Any diesel engine would require that the fuel line feeds to the injectors would have to be removed or at least loosened to crack the injectors themselves or you would damage the steel fuel lines. So I assume that he cracked the fuel lines above the injectors themselves. How many fuel lines did he have to crack before the engine shut down as normally they will run on less than all cylinders though be very rough?

Engine runaway or run on is usually due to a plugged crankcase ventilation system which will result in pressure in the crankcase and drive engine oil past the rings into the combustion chamber. Also, black smoke and fuel in the exhaust is usually a result of a high fuel content in the fuel/air mixture which can sometimes result from plugged air filters or from a faulty injector pump which is improperly timed.

Normally these engines have a shutdown solenoid which requires activation (power on) to cut off the fuel flow from the lift pump to the injector pump. this is how my 4 cylinder perkins engine in our CT 43 Mermaid in cuba is set up. Our 6 cylinder M 135 Perkins on our CT 56 is the same and this is a 1999 model. Some engines have mechanical activated fuel shut offs and most newer non marine engines have electrically operated fuel solenoids which require power to be removed to shut down the engine.

I think you may be experiencing more than 1 problem at a time in this situation. Black fuel could be as a result of a biological condition, breakdown of the fuel lines themselves or just plain dirty fuel from the supplier. When we were in Indonesia last year we had to clean our racor's weekly to empty the sediment from the bowls which was just carbon particles. the fuel was black right out of the barge but it was the only fuel available.

I had a mentor who's favourite saying was "keep it simple stupid" and he was right 99.9% of the time. I believe that your runaway engine is a result of a faulty injector pump combined with a problem with the fuel shut off. Just to be sure, I would perform a compression test on the cylinders just to make sure that I was not going to waste a lot of money on an engine that was worn out and if results were within acceptable parameters then I would pull the injector pump and have it rebuilt and replaced by a professional to ensure that the timing was correct. I would also replace or prove the shutdown solenoid as if this is working properly then even if the injector pump is faulty it should shutdown the engine by cutting off the fuel source. As an injector pump would normally be rebuilt or replaced along with an engine rebuild this will not be a waste of money.

It might be possible for oil to get into the fuel system through the lift pump but I have my doubts. This is cheap to replace as well though.

Good luck and keep us posted.

I would not trade our heavy displacement "leaky teaky" for the world. Well, maybe for the Whole World.

Tim

[zeehag]

mechanic cracked all 4 injectors.

no turbo on a 4-108.

can i kill seagulls now....

[Sailmonkey]

Originally Posted by zeehag

mechanic cracked all 4 injectors.

no turbo on a 4-108.

can i kill seagulls now....

No seagulls here, just trying to help

Did the mechanic crack the fuel lines to the injectors, like you would to bleed the engine, or like you would to replace the injector.
If the latter, the mechanic is braver than I to spend that amount of time over a runaway engine!!!

This smells like a bad injection pump!

[MarkJ]

Originally Posted by undercutter

favourite saying was "keep it simple stupid" and he was right 99.9% of the time.


Tim

Yep, keep it simpple. Theres gotta be a reason. The catch all phrase that a new engines needed doesnt aapproach a diagnosis. Theres gunna be a reason and like Tim says its probably simple.

[Jim Cate]

So I am a bit confused here:

I thought that a runaway engine was running on lube oil from the crankcase... so how does cracking the injector lines stop it?

Am I missing something ?

Cheers,'

Jim

[zeehag]

is magic....i am still trying to figger it all out....he cracked injector, is what he told me--he was pale and shaky when done. scared pooless actually and needed a month and half vacation....so iam still trying to figger this out.

on top of this i got monkey bit on base of index finger and need to divert funds to medications for prevention of viruses and bacterial infections...we do engine next month, i hope.

[Jim Cate]

Originally Posted by zeehag

is magic....i am still trying to figger it all out....he cracked injector, is what he told me--he was pale and shaky when done. scared pooless actually and needed a month and half vacation....so iam still trying to figger this out.

on top of this i got monkey bit on base of index finger and need to divert funds to medications for prevention of viruses and bacterial infections...we do engine next month, i hope.

Crikeys, Zee, what were you doing with your finger in a monkey's mouth?

Hope that it was a healthy monkey and that there are no repercussions... jeeze, the things that happen to cruisers!

Cheers,

Jim

[River Cruiser]

If cracking the injector line nuts killed it then the culprit is most likely the governor or rack in the injector pump, a rebuild would be my next step & may as well rebuild the injectors also. Good luck & don't feed the monkeys;-)

[Sailmonkey]

Originally Posted by Jim Cate

So I am a bit confused here:

I thought that a runaway engine was running on lube oil from the crankcase... so how does cracking the injector lines stop it?

Am I missing something ?

Cheers,'

Jim

Yep, a traditional runaway is running on lube oil.
What zee posted in her first post is not how you douse a runaway.
There be fuel pump problems here, yar.

[sabray]

I'm thinking one of the pumps has cross contaminated oil and fuel. Is the lift pump mechanical? Maybe at the lift pump or injection pump. You get fuel n the oil and oil in the fuel. I think way back there was a thread about the seal between the lube section and the fuel side potentially doing this.

[MarkJ]

Poor monkey! The monkey may need meds!

[brutb]

MarkJ,
If we are not careful, we may have to bail Zee out of the local pokey for animal cruelty. Letting a nice peaceful monkey get all infected with Leaky Teaky juice could endanger it........

[MarkJ]

Did the monkey piddle in the fuel tank?

[zeehag]

naaah no monkey out of his house which isa cage at hotel sand... friends of mine run sand bar--good place now to hang out as long as you have your own stash of autan, and the pool is now clean and clear--lol garden is prettier and monkey is fatter, now that he has eaten my hand...
today i gave him 2 tiny bananas and a piece of french baker pastry--he chirped happily and i went away---he isnt getting scritchys any more... mean ol me.... and my finger is improving with good cmst..
when you are monkey bit, immediately wash deeply with soap for 20 minutes minimum, gotta take antibiotics and antivirals and in not low doses, and hopefully the monkey was tame-ish..and anti inflammatories-i am taking toradol sublingual..wonderful stuff.. so i take pills for a coulpla few weeks. i still have all the meat of my finger. no chunks removed. he realized i wasnt a mango and spat my finger out, thankyou chachi--so i only have 2 punctures in my index finger. is all good. we both alive despite poisoning by the other...
so far.

oh yes...and an ex navy SEAL has folks who do diesel engine repair..we be having plan b

concur with idea of injector pump..if only because it makes sense and the repair guy i been using thinks that is not possible....lol..we see.....