Service manual for NL M844k Lugger engine?

[MikeP]

I am trying to locate the tech manual for that engine but haven't found it available at all on line - either as a download or to purchase as a hard copy or CD. All I can find are operator and parts manuals, which I already have as the hard copy that came with my NL.

The NL site does not show a service manual to be available. I suppose they are trying to keep their techs in business!

I can do the work without the manual (I'm now thinking injector pump problem), but having the service manual would save some time.. Any ideas re a source for the manual?

 

[MikeP]

Fixed

FIXED! ...well, maybe.

Discussed it with a GOOD NL Tech in MA. (there are less good NL techs elsewhere as I discovered... ) Turned out the problem has nothing at all to do with the engine - it was an issue with the voltage regulator which had caused the generator to bog down. Basically, the regulator shunted the generator coils so as to essentially provide a huge load for the engine - far beyond what it is designed to handle. So the engine went to full fuel to provide enough power but there was insufficient HP to spin to normal RPM so it ended up with huge quantities of fuel for the rPM.

This morning the Genny was doing as it has been doing since "failure" - running at about 1/2 speed and copious quantities of black smoke. At his very first suggestion (Joe in the MA NL branch) I turned off the voltage regulator breaker which "turns off" the generator section. The engine then started/ran perfectly. I turned the breaker back on and the engine continued to run normally and all generator power was normal. So obviously, something went awry internally in the regulator section during the night at anchor when the Genny went south but resetting the breaker this morning "cured" it.

Joe pointed out that (as we all know) electronics don't usually fix themselves. However, he said he has seen that happen on occasion and recommended the usual - break/clean/remake the internal connections, which I did, also reseating the 5 plug-in relays. So it may be "fixed" or it may not. Since it's working properly now, the only thing we can do is watch it and, if it does it again, replace the regulator board. It could be a electronic component issue that occurs when the jenny is very warm. So the only thing to do is see if it does it again.

But at least I know what the issue is and that it has nothing to do with the engine...

For NL questions - electrical or mechanical - call Joe in MA at 978 258 7412. They also sent me a PDF of the workshop manual via email. You can't beat that kind of support!

 

[MikeP]

Oh Oh, not quite so simple...

OOPS...Not Fixed!

Today I decided to do an oil change on the Generator and when I started it up to warm it, it exhibited the exact same symptoms as previously - lots of smoke, low RPM. This was with the generator coils on OR off. So that led me to believe that that may not have been the issue at all and that perhaps some coincidence was involved with that...

So today I did the usual fuel injector check and found that cracking injector #4 made no difference in engine RPM. Cracking 1, 2, 3, each reduced RPM. So it seems as if EITHER the injector has failed or there's no compression in that Cyl. Since I have never heard of compression just going away on it's own (valve settings are correct) I'll assume it's the injector for now... $179 each. (there's plenty of compression by the old, reliable "thumb on the injector/spark plug hole" method.

Yes, I have a diesel compression tester that I used when I did a tune up on my 8V71TI's a few years ago but I'm not sure where I put it. Hmm maybe Cheryl has one!

Just kidding with that last - the tester is in the storage shed up the road...I think.

 

[Avenger]

Swap the injector with another and see if the problem moves.

If you're going to spend $179 on that injector please send it here. I could use the extra money.

 

[MikeP]

Swap the injector with another and see if the problem moves.

If you're going to spend $179 on that injector please send it here. I could use the extra money.

Well - that's the price of a "genuine" new NL/Lugger injector with a 6 month warranty. I have no idea who actually makes it...maybe some guy and his son in a garage in Zhouzhuang, China.

 

[Avenger]

Northern Lights uses Ishikawajima (A.K.A. IHI) engines for their smaller generators. AFAIK all made in Japan, as are the fuel system components. Give me the # off the injector and I can tell you what a new one costs from the O.E. fuel system supplier.