turbo chargers


You guys ever heard of fuel polishing? Fuel company comes and removes the diesel, filters it through huge Racors, and then refills the boat and adds an additive. That is what is happening at my dock, next Wed. I will let everyone know the outcome. Everyone I have talked with here, in Florida, seems to be incredulous that I have never had that done in the 12 years I have owned this boat.
 
Yes I've heard of it, most time it is needed for diesel that sit's for long periods of time. In your case it would be warranted. If the boat was used more there would b less chance of algae build up. They make products which treats the fuel and stops algae growth.


I still find in most cases it's where the diesel is coming from. We have heavy equipment contractors have trouble quite often because they have to buy diesel where ever there working. I have several pieces of equipment and have never had an issue because I get my fuel from a location I know has high turn over of fuel.
 
I've also heard of it, again usually associated with fuel that has been sitting or possibly contaminated. I've seen instances where the fuel tanks, that feed the pumps have become contaminated by various things, truck driver putting wrong fuel in, cover left off or loose, letting in water/mud/runoff, or the refinery/fuel supplier having issues. If no one else at your marina has issues with the fuel, and you run your boat regularly, it shouldn't be required. But, hey, you never know, if it works, that's great!!
 
I never had my fuel polished in 10 years. I never had fuel stay in the tank for a year. It gets very hot in FL over the summer and that can cause a lot of condensation in the tank. That's your worst enemy. I leave my boat in FL for the summer when I am not there but I fill the tank before I go. There is less room for condensation in the tank. Your dirty filters in a few months are a good sign of dirty fuel. It sounds like your boat sits for long periods of time. Fuel polishing may be your solution.
 
The fuel was polished yesterday...they filtered 250 gallons and what would normally take 4 hours, took all day....9 to 5. Why, one might ask...they had to go to another job site (truck) to get special equipment because the fuel lines were extremely hard to get to. It seems that everything on a Formula or, at least the 41 PC, is hard to get to. My boat guy cringes every time he is asked to change the impellers. My comment to the guys filtering is that I would think they would come to a job prepared for any kind of boat and circumstance and, I was a bit incredulous when they said that normally smaller boats do not have the fuel polished....only large yachts yet, when I mentioned that I have never done this before in the 12 years of owning this boat, they were surprised. Divergirl is going to be sea trialed today after the Racor fuel filters have been changed so, I will let all know how this affects the turbo performance.
 
Sounds good, look forward to hearing the results.

As for the comment that they were surprised of it not being done, again if the boat was used more there should not be a need. The other side, that to more it's used the more often the filters will be changed. I would suggest adding some additives to keep the algae from building up. As for the folks that make a living polishing fuel, I would be floored if they said anything other then being surprised.
 
Ok, Divergirl was sea trialed and although performing better than before fuel polishing and filter changing, the engines register 1200/1300 RPM while engaged and in neutral right up to 2000/2050. The fuel pressure is perfect. So, in neutral they are spooling & whistling away and while engaged they are not spinning enough to hear them. My friend the boat captain suggested maybe an electronic default issue in the shifting/throttle control? The control keypad and SB potentiometer were changed in October. I contacted the company that did that work and he said "the turbo chargers di not effectively kick in during a no load condition...if the fuel filters are clean, I recommend the turbo chargers be checked. They sometimes will stick if not used under load for a period of time". Then he suggested that the bottom and the props were perhaps not clean. I told him the turbo chargers are spinning when turned manually so, not appearing to be sticking and, I have a guy who cleans the bottom and running gear monthly. The boat was hauled, bottom cleaned and painted 1 year ago.
 
Turbo's will not build much if any pressure in neutral, just not enough load. Things that can effect turbo pressure, exhaust restrictions and intake restrictions. The issue which keeps me from thinking anything with the motors is both are doing the same. If one was doing better/worst then the other then I would start looking for a motor problem. With both motors doing the same, I look for what's common to both, as with throttle controls.

What was the fuel pressure?

Before checking turbo's I would like to know what the intake pressure is, again if both the same, it's not the turbo
 
I hate to beat a dead horse with a stick, but... How is your bottom and running gear? I know you said it was fine, but this is the time of year that water temp changes and barnacle can bloom fast.
 
Alas, I was going to try to get Divergirl out again for another trial but, I could find not one person who could go with me, it being Easter and all. Another boat captain friend suggested that the additive might need time to make it through to the fuel injectors. And then, another suggestion was that because there was so much sludge in the Racor filter bowls, that maybe the fuel injectors need to be pulled and cleaned.
 
IMO if crud had made it past the filters the motor would have a real hard time idling. Then you could also get a miss in the motor in higher rpms
 
Divergirl
I would suggest that you have those secondary fuel filters on the engine replaced also. Put some hours on that beautiful boat.
 
Ok all....took Divergirl out myself today. Turbos not kicking in....got 1400 RPMs full out throttle. The fuel has been polished....racors changed....fuel full.....nada. Someone suggested "fuel management problems"....like computer keypad control. Both engines were spewing black smoke a few weeks ago, now it is just port.
Engines running fine...fuel pressure, oil pressure, everything looking good.
 
The 41 diesel has a smoke limiter and does not allow the motor to receive more fuel until boost pressure from the turbo is increased. With black smoke this leads me to either the limiter is not working or there is sufficient boost pressure to allow more fuel. Smoke comes from more fuel then it can burn. Things that can increase smoke is insufficient boost pressure, which can be caused by Air intake or exhaust restriction.


Restrictions:
Air filter
Inner cooler
intake path way hose/manifold
Turbo vanes damaged or worn
exhaust exit path way hose/muffler

Turbo boost pressure at WOT should be 100kPa/14 PSI at +20C/68F.

Now just port engine is smoking, but how are you determining that the turbos are not working, from sound, pressure gauge or just no power? There should be a hose going from the intake to the injection pump to which is how the limiter is controlled. BTW turbos don't kick in, they just spin and as pressure is built up more power is obtained.

Your saying pressures are fine and I'll guess this is from the mechanic saying there ok, but do you have any of the actual numbers?

I'm wondering if someone misadjusted something on the injection pump and/or throttle linkage.
 
Hi AllDodge...I am just reading all of the gauges which are reading fine...oil pressure, fuel, no overheating so, no one is telling me that info. Making the assumption that these tings are fine because the gauges are not indicating that anything is wrong. There is no power and I do not hear them spooling up. In regard to the possibility of a misdjustment in the throttle linkage. The controller keypad was replaced last October and of course, I associate that with the throttles...so, do you think that might have anything to do with this?
 
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