892 Injectors

[Sadey]

In preparation for our long journey north we are trying to get the motors prepped. Both motors will turn 2350rpms and run 150-160 degrees at 1500rpms and 170/180 at WOT consistently. We get a little soot from the port motor and no apparent sooting from the starboard side. We also get a greasy film all over the aft-deck isinglass. The bottom is clean (diver once a month) and the props (32x29 4 blade Nibral) are in good shape.
No record of the last time the injectors (145's) have been serviced. I'm considering having the injectors all replaced instead of rebuilding in the interest of time. Thoughts? Suggestions?
Thank you in advance.

 

[Captain Ralph]

Do not insert problems so close to your departure.
New or rebuilt injectors don't mean flip from each other. Ive had problems off the shelf for both.
Having the injectors popped and matched just before install is your best insurance if you must replace the injectors.

I'd pour some Marvel Mystery Oil in one of the Racors and run it out when away from the docks.
Replace the air filters and go have fun.

 

[rustybucket]

I just went through the injectors on our boat. I HIGHLY recommend having YOUR injectors rebuilt at RPM diesel in Lauderdale. They had a very quick turnaround and I've been very pleased with the injectors so far.

If purchasing new/already rebuilt, please be very wary of the source of the injectors.

 

[Sadey]

To be clear are you saying not not bother at all? Also can you give me a little more splaining on the MM? It’s my first diesel so be gentle.

 

[SKYCHENEY]

Don't replace the injectors. First have the engines tuned (if you haven't already). I mean, have your mechanic run the racks and adjust injector and valve heights. Then, if you still have a problem, figure out which injector(s) is bad and replace that one.

You can try to clean them as suggested by filling the racor with your favorite cleaner. Some like MMO, some like ATF, and others like Diesel Kleen, etc. Be aware, however than most of what you put into the Racor never makes it to the injectors as it is returned to the tank.

No matter what you do, you'll still have some sooting. These are detroits. What you don't want to see is a sheen of fuel on the water or heavy smoke at any speed.

 

[rustybucket]

What you don't want to see is a sheen of fuel on the water or heavy smoke at any speed.

sheen on the water needs to be isolated to oil or fuel, maybe throw an oil absorb rag on it and give it a sniff. This could be a heat exchanger that has failed or is about to fail.

 

[SKYCHENEY]

sheen on the water needs to be isolated to oil or fuel, maybe throw an oil absorb rag on it and give it a sniff. This could be a heat exchanger that has failed or is about to fail.

Or unburned fuel from an injector with a bad spray pattern.

 

[Captain Ralph]

To be clear are you saying not not bother at all? Also can you give me a little more splaining on the MM? It’s my first diesel so be gentle.

If you are leaving within two weeks, just run the racks maybe, but don't insert a problem.
If you have been a dock queen for a while, your problem may clear up with some MMO (Not ATF)
and good ole running as Detroits prefer.
If you have not been at temp and above low speed runs in a while, your Air Box could be full of grunge.

You have to think of 92s as the racehorse, at a mules pace it's dirty.

What's a MM?

 

[Cricket]

I would not leave on a long boat trip in the next few weeks with everything that's going on, especially towards up north.

As far as the engines go having a DD pro perform a tune up and take a good look for other issues that could be causing the sheen is great advise,
not going to get any better if left alone, probably worse.
Also, I'm not a big believer in the "liquid miracle diesel engine potions"" other than Biobor to kill algae, although I do think Sea Foam used in gasoline actually works.

 

[Sadey]

She hasn’t been a dock queen lately. We have put about 75 hours the port motor and 25 or so on the starboard side. Everything is running well just a little soot from the port side and the film that develops on the stern. I don’t see any sheen on the water. The reason for wanting to look into this is lack of history on service. The DD mechanic that has been working on the boat for a few years and has never tuned or dealt with the rack or injectors. We don’t leave until May 7th so I have time. I’m inclined to have RPM rebuild since I know even new ones need to be tested and RPM is 10 minutes from my condo. That is if their open.
I’m looking at this as inevitable maintenance and since my guy is very close and reasonable why not do it now. For sure I’ll have him tune and adjust at a minimum. Is flawed thinking.

 

[kelpy]

Pull all of the injectors and, as stated prior, drop them off at RPM Diesel injector shop for cleaning and testing. They will fix the bad one on the port side. Then have RPM reinstall and tune up the engines. Carlo is the tech I use on the 16-92s.

 

[Cricket]

You should do it now while RPM is able (still open).
If it was me I would have RPM do the the whole project (remove injectors, test-rebuild, install, tune up) that way if there's a problem after you leave it's on them.
Would also make sure you have at least 1 spare injector and the rest of the parts that go along like jumper lines, rocker arms etc. That way you have the parts and only need a DD guy to put them in if something goes bad on the trip.

Been awhile since I had 8v92's, started caring lots of spares after getting stuck once for a few days because the DD guy had to wait for parts.