Yammer Problems and Black Smoke

[HappyMdRSailor]

Oh dear....

I've neglected my EGR on every boat I've ever had...

***off to Autozone***

[Old Swampy]

I, too, suspect faulty injectors and point out that when you disconnected the fuel line from the engine, you could have introduced something that could have fouled an/all injector(s).

[GrahamHO]

If your tachometer is correct I think 4300 is too high revs for this engine. From memory it should be around 3600 rpm which suggests an incorrect governor setting.

When you get black smoke running it in gear are you under way or running it against the mooring lines? If against the mooring lines, black smoke would be normal at full throttle going nowhere. Doing that overloads the engine. It should run OK at about 1900 rpm against the mooring lines which can be a good way of "exercising" the engine at times when you aren't going sailing.
If you are under way and getting black smoke it might be something like the underwater sail drive boot glued onto the hull has come loose dropping down and creating a water brake.


Even if your governor setting is wrong I don't think that would cause smoke but it could result in over revving and damaging the engine especially running it full throttle in neutral.

[Bluebeard]

30 seconds on google tells me that yours is a naturately aspirated engine so i feel a little more confident about my two peneth.

Black smoke is overfuelling, often caused by worn injectors but that doesn't happen instantly. What amkes more sense is that the engine is trying to increase speed but something is stopping it, it could be mechanical and external to the engine in which case it would have to be in the saildrive/prop, or it could be gas flow either inlet or exhaust, air filter or other blockage not letting enough air flow for the fuel that is being injected, or valves? that would seem unlikely if it revs freely unloaded.
How about injector timing out? The engine would still inject the same amount of fuel but at the wrong time.
Is there a timing mark on the crankshaft pulley, adn can you turn it over by hand and hear the injector squeek?

Ian

[sailcrazy]

Our Yanmar (4JH-TE) exhibited similar symptons, and after a long search finally found at least one of the culprits. Have your injectors checked! Despite a recent total overhaul, our injectors were set for the wrong pressures and were giving a very wrong spray pattern. In addition, our injector pump had been rebuilt during the overhaul.....but they "forgot" to use any gaskets when they reassembled it!!! Between the two, and retiming the engine, our Yanmar suddenly regained her P & V, and significantly reduced her smoking at high power settings. FWIW

[Soulflyer1980]

Thank you very mich guys for all the Input, I really appreciate it.

Yesterday I took out the cone clutch again and pretty much eliminated the sail drive as a fault. Even tried to check axial play in the Prop shaft, if its pressing itself in forward onto the anode and creating the load only with the rotation of the propeller. Difficult to tell but I'd say there's no issue.
On the Engine I took out the Injectors and gonna have them checked today, maybe one was dripping. Since I don't have the Turbo my best guess is Injectors and if they are ok then I'm gonna wrap my head around how to adjust the timing (CW and CCW) how would I find the correct adjustment?

@Truemettle When your mixing elbow was blocked, did that affect the RPMs under load or without? I can't imagine reaching max RPMs with no or only little air going out of the engine. Little Air comes out, little Air can go in but same amount of diesel so you are running to rich hence the black smoke. I'm gonna check my exhaust today and take everything apart.

@seasick Yes I thought of that as well but I'm more comfortable adjusting carbs then injection pumps, so thats gonna be my last option since I don't know how to adjust it correctly. I checked for bumps and stuff but it all looks good, might happened before the paint job.

@HappyMDRSailor My clutch wasn't slipping for more then 3 engine hours, I am sure the engine is not all gummed up

[Soulflyer1980]

@ Old Swampy The diesel lines have never been opened this time, can't be the issue. And even then it wouldn't Rev normal with one or all injectors clogged.

@GrahamHO I am comparing my 'faulty' engine on the starboard side with the good one on the port side. Both are running exactly 4300 in neutral. And I have been testing them out in the blue but cant remember exact figures but same problem. Now I run them against the docklines, good engine does about 3500 with prop engaged, 'faulty' engine doesn't reach 2000. And theres no clutch slippage on any side now, the noise and push of the prop wash is about the same ratio to the RPMs. Propeller, Saildrive and Hull are as clean as a whistle and I pretty much ruled out the sail drive as an Issue. Still thinking of Axial play in the prop shaft and rubbing against Anode creating too much load but unlikely in my opinion.

@sailcrazy I will have my injectors checked but they haven't been out in ages or tampered with this time. The whole Diesel system wasn't touched. It could be that the Pump got a knock and timing is off.

@Bluebeard I checked the intake side and it's as clean as you would expect it, there's no obstruction. Haven't checked the exhaust side yet or the mixing elbow but I find it hard to believe that anything blocked would still make her run max RPMs without load.

Thank you very much, lets see what comes out of it.

[Kenomac]

When our turbo was not functioning correctly, we had the same symptoms... An engine bogging down under load. More fuel being thrown at the problem, when the issue is not enough air.

[Bluebeard]

There can only be so many possible problems:-

1) Mechanical, external to the engine. Some "drag" once it is in gear, is it the same in reverse? and you have checked everything so it seems unlikely.

2) Air flow. A diesel pulls the same amount of air through at low or high throttle, there is no choking, so if the air flow was restricted, then at low throttle there could be enough air for the small amount of fuel to burn cleanly. Check the exhaust side and also the valves, are they opening the correct amount and does the valve timing look right.

3) Injectors are a classic failure point, but they are putting fuel into the engine so it isn't obvious.

4) Pump timing could be the problem. It would be like running a petrol engine with the ignition either too advanced or too retarded. Why it could have happened is altogether another question.
The only way I can think of for checking timing is - can you hear the injector squeek? If you can turn it over by hand then the squeek should be there even at very low turn over speed. Where in the cycle is the squeek happening. The manual or a dealer/ mechanic should tell you where it should inject.

Good luck

Ian

[Truemettle]

Hi, the engine started and idled normally and we put out to sea without initial issues, my tach was not working at the time but I was running along at normal speed. After about a 1/2 hour of running normal under load, the engine just started throwing smoke thick as fog, I backed the throttle down, shut off the engine, checked for obvious problems, removed the breather. I started back up normally but when I throttled up, the smoke would appear. I could run at about 1/4 throttle without issues. Once back at the dock, I removed the exhaust hose and found the mixer plugged, I pulled the mixer off and it was clear that was the problem. I replaced the mixer, and the water lock as my old one was in pretty bad shape, and the engine has been working great ever since.

[Charlie]

Soul Flyer I have been following this post for the last couple of days but didn't comment because everything I had to say had already been covered. I own a 4JH4E. I was having problems with it. The engine would spit out a lot of smoke whenever I put it at a high rev. I was also making oil. I took it to a number of experts and while there were lots of ideas no one could fix the problem. First thing to do is to check your oil level. If the oil level grows and becomes thinner there is a strong possibility that there is diesel fuel in the oil. There are a few places where the diesel can enter the lubrication oil system. The most common is through a break in the diaphram of the lift pump. The manual has a procedure to check this. I replaced my lift pump and the problem went away -- for awhile. A few months later the same problem came back. I ended up having to change the oil frequently and keep it at low RPM all the way from La Paz to San Diego. I installed an electric fuel pump and bypassed the mechanical one and it went away again-- for awhile. Finally with nothing left to try I decided that the problem was most likely in the injection pump. It took me a lot of courage to remove the injection pump. I had to fabricate a special wrench to enable me to take apart some of parts. But taking off and replacing the injection pump was not as difficult as people say. The key was to mark the engine block and the injection pump with a deep dimple from a center punch. This allowed me to replace the pump in the exact same position and not retime the pump when reinstalling the IP. After removing the pump I took it to a diesel IP rebuilder. They tested it and found no problems. Tested it again and still no problem. Finally they left it on a pressure test for 45 minutes and just as they were going to pull it off it started to bubble. I reazlized that this was a factory problem when I had done my repower but it took me years past the warranty to figure out the problem.

If you are going to have your IP tested and rebuilt it is a good idea to take it to a rural area where there are lots of agricultural machines. When I had my injector done they were half the price of the marine oriented buisnesses.

Here is the link to my post about it -- http://www.cruisersforum.com/forums/...ump-91210.html

[Soulflyer1980]

Hey guys I'm still head over heels in my engine bay and trying to figure out what the issue is. Recently I have taken out the whole exhaust system, beginning with manifold over the mixer to the tubes, water lock all the way to the through hull. All as clean as a whistle (black one thought) and nothing is clogged. I have taken out my Injectors and given them to a Bosch service, even though a bit clogged and funky spray pattern the service guys said it couldn't have caused the described problems, if any really apart form a little lack of power.
Now, while undoing the diesel lines at the injectors, I noticed the center one is free flow pissing diesel, nothing out of the other two. I thought that might be because of the 'self bleeding' system or similar and, depending on crankshaft position, one will free flow at a time. So I turned the engine by hand, counterclockwise from stern, but number one or three never piss diesel and number two doesn't stop! What's that all about?


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[Soulflyer1980]

Now of course I am a bit hesitant putting it all back together...

@charlie that would be the next step to have the IP checked out and replaced, sadly enough I don't know if the timing is right or not. I know that both engines are running, in neutral, at 4300 RPMs. Someone said my timing is out but then it must be on both. On the second engine wasn't done anything though and she purrs like a cat. I know the output rating at crankshaft is 40hp at 3800RPM, what I couldn't find out if that's a figure with or without load attached. I'm a bit confused...

F


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[paulajayne]

Have a look at "Bleed off test" which can be used to identify a bad injector.


Each injector does not use all the fuel that is sent to it and has a bleed line which recycles the unused / not required fuel.


The test measures all the injectors at the same time and the faulty one will show.


Can be a bit fiddly to do and have to have the correct adaptors for your injectors.

[Soulflyer1980]

Originally Posted by paulajayne

Have a look at "Bleed off test" which can be used to identify a bad injector.


Each injector does not use all the fuel that is sent to it and has a bleed line which recycles the unused / not required fuel.


The test measures all the injectors at the same time and the faulty one will show.


Can be a bit fiddly to do and have to have the correct adaptors for your injectors.

Yes that I know, I just had all three injectors serviced, cleaned and pressure readjusted. All good there. What I am confused with is why number two injector pipe is flee flowing diesel at the disconnected injector. Doesn't matter how much I turn the crankshaft, number two is free flowing and nothing out of one or three.


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