MEP-1070 Ran away on startup

[yamaha415]

Hey guy scratching my head here. Finally got the replacement fuel return line for my MEP-1070 I pick up at govplanet as a non runner. Anyways went to start it for the first time for me and it was sputtering and producing lots of smoke. Noticed that most of the injector lines where loose so I tightened them and retried starting. It come much closer to starting after this, but failed to do so and continuing to produce lots of smoke. I also noticed that on the second attempt of starting the intake hose was starting to crush. Well for better or worse I took the intake hose off right as in enters the engine and tried again. This time it fired, with higher RPM's than I was expecting (i attributed it at the time to first start after many years and clearing things out). Then the RPM's kept rising, smoke billowing and it became clear the engine was running away. The emergency stop was pressed to no effect, so thankfully I had the intake hose off the engine so I covered that with a cardboard box and got the engine to shut off.

It threw the Fault code 234 High Engine Crankshaft Speed/Position-Most Severe. I'm at a loss for why it ran away with the turbo being taken out of play with me having the intake disconnected.

Hoping you guys have some ideas. I was able to get it shut down pretty quick so I'm not thinking blew the engine. However, it got me thinking that its likely the last time it was run by the military it could have likely ran away on them (the air cleaner lid and filter was missing and inside the engine compartment has some white and redish powder which might be fire extinguisher residue). If thats the case who knows how long it was until they were able to get it shut down. Not sure how far I should take this one so I'm hoping you guys have some clever ideas as to why it might be running away.

Thanks

 

[Ray70]

Could you give us some background info on your 1070, including hours etc?
I have no experience with your model, but in general a run away diesel needs to be receiving a fuel source that is uncontrolled by the machines control systems. First thing that comes to mind is an oil leak feeding into the motor such as through a blown seal in the turbo.
If possible, I'd try looking in the turbo / intake area for signs of oil.

 

[yamaha415]

Could you give us some background info on your 1070, including hours etc?
I have no experience with your model, but in general a run away diesel needs to be receiving a fuel source that is uncontrolled by the machines control systems. First thing that comes to mind is an oil leak feeding into the motor such as through a blown seal in the turbo.
If possible, I'd try looking in the turbo / intake area for signs of oil.

1400 hours on the digital display 974 hrs on the mechanical next to the fuel tank. I agree on the turbo leaking as being a potential external fuel source. But, with me having the intake hose disconnected at the engine doesn't that takes the turbo out of play and thus the possibility of getting oil through a leaky turbo seal? I'm not a diesel expert by any means so let me know if that is incorrect. Could it be getting oil any other way other than through a bad seal on the turbo (no sign of oil in the intake)?

If you agree with my thinking, my next train of thought was the injectors might be grounded out and all just dumping fuel, maybe a faulty ECM?

I guess another thing to add would be once it got running it shot alot of black liquid out the exhaust and made a mess. This seems to fall in line with wet staking from what I have heard. No indication it had been wet staked before unless someone spent some time cleaning the cabinet as it was all OD green.

Appreciate all the help

 

[Ray70]

You are correct, I mis-read where you took the intake hose off. I didn't realize it was off the intake not air cleaner, so yes.... you have eliminated the turbo from the equation. Your thinking about the injectors just dumping fuel is a definite possibility. Unfortunately I'm not experienced with that model so you may need to research the TM to find how to troubleshoot it. If electronic injection maybe you could unplug the injectors, attempt to start it just to try to blow out any excess fuel in the cylinders, then plug 1 injector back in and try starting. Maybe by doing 1 at a time you can find out if you have 1 stuck injector or if they are all wide open due to an electrical problem?

 

[yamaha415]

You are correct, I mis-read where you took the intake hose off. I didn't realize it was off the intake not air cleaner, so yes.... you have eliminated the turbo from the equation. Your thinking about the injectors just dumping fuel is a definite possibility. Unfortunately I'm not experienced with that model so you may need to research the TM to find how to troubleshoot it. If electronic injection maybe you could unplug the injectors, attempt to start it just to try to blow out any excess fuel in the cylinders, then plug 1 injector back in and try starting. Maybe by doing 1 at a time you can find out if you have 1 stuck injector or if they are all wide open due to an electrical problem?

Thanks Ray. That sounds like a good idea. What am I going to be looking for as I plug the injectors back in individually? Change in smoke? it shouldn’t be able to fire with only one injector plugged in correct?
Also does the black liquid that was raining out of the exhaust typically happen on a run away or is that evidence of the generator being wet staked the last time the military ran it?
Thanks again for all the help

 

[Ray70]

Yes, I bet it would have a hard time running on 1 cyl, but it may run. It definitely won't run very well. As you plug in more injectors just see how it reacts.
If you see evidence of unburned fuel in the exhaust or a runaway situation you will know you are closing in on the problem cylinder.
Tell us what you discover and we can try to figure it out.

 

[Guyfang]

Check speed sensor position sensors for tightness and cleanliness and ECM connections and the fault code is in the manual.

This is an answer from someone who KNOWS this gen set.

If you do not READ THE BOOK for this gen set, and read it several times, this is a hard set to troubleshoot.

 

[yamaha415]

Check speed sensor position sensors for tightness and cleanliness and ECM connections and the fault code is in the manual.

This is an answer from someone who KNOWS this gen set.

If you do not READ THE BOOK for this gen set, and read it several times, this is a hard set to troubleshoot.

Thanks Guyfang I will look into that as well. Really apricate all the help from everyone. Just curious if it was a problem with the speed sensor I could see that causing the high RPM's, would this still be the case with none of the electrical shutoffs working to stop the motor? Does a speed senor out of adjustment have the potential to override the engine electronics?

I will report back with my findings