Realizing from the previous tests that fuel delivery was not the problem but rather a restriction of air/boost to mix with the fuel. The servicing of the aftercooler no doubt helped with air flow but I decided to change the intake filter and try a less restrictive high flow performance filter. The results were positive, boost went from 5 psi to 15 and rpm increased to 2300. A big improvement but still not the 2800 that the starboard engine produces.
I will continue on with leak tests to ensure I am getting all the boost I can and the system is leak free. Can someone please tell me know what kind of boost numbers I should be obtaining for this M2 engine with the H1E turbo?
Tony, thank you for your excellent guidance as I worked through the troubleshooting process, Any suggestions on the turbo, boost, and increasing rpm to specifications is appreciated.
The parameters had changed, there was black smoke because I was forcing the system to think that it was getting higher boost, moving the aneroid diaphragm down allowing more fuel but not air causing a fuel air imbalance. Read some of the threads before and you can follow what we were trying to do.
Tested aneroid at 20, 25, 30, and 35 psi. All pressures produced the same results of black smoke at 1600 rpm and no further throttle response after 1600-1800 rpm. Boost was measured from the existing aneroid line while the tester was hooked up and only measured 2-5 psi.
The minute I throttled back below 1600 the black smoke disappeared in all cases.
Everything was leak tested prior to performing the aneroid test to ensure accurate results.
Hi All,
Sea trial result a little better, 2000 rpm, but I’m not so sure it wasn’t the starboard engine dragging up the port. Static boost at 2000 was 5 psi.
I’m going to do a “fake boost” test next. I have built the device pictured below so that I can pressurize the aneroid to simulate 20-30 psi boost and maybe I can loosen up the diaphragm if it is stuck. Also, I will be doing a boost leak test and have to build the device to test it. Stay tuned for further results.
Tony, I have the equipment to set up the “fake boost” and will hook it up if my test run today is unsuccessful in producing higher rpms. I plan to go right into the aneroid connection with a regulated psi of 20 lbs static.
Thanks again,
Hi Dan,
The cause was never sorted out. I have done everything Tony has advised me to do and just completed reinstalling everything yesterday. I paid special attention to the couplings and tubes to make sure I didn’t have any leaks and everything was sealed up good.
I’m new to the whole diesel boost and aneroid thing so I’m not real sure when and how much boost I should be reading and under what conditions? I didn’t have any in neutral at the dock when I revved it up to 2000 but then I didn’t really expect any without a load. (any guidance in this area would be appreciated)
I plan to take the boat out tomorrow to see if it will now get over 1800 and run like it should, I have gone over everything from the turbo to the intake manifold (turbo spins freely and smooth and does not move in or out or side to side when operated by hand). I will post results after my trial cruise.
Cleaned, greased up and reassembled. Ready to go back on port engine after installation of anodes.
Tony,
Here’s the photos, didn’t look too bad except for the impeller parts the previous owner left for me! This is off the engine I am having a problem with and it came apart real easy so it must have been lubed up when serviced before, all removed by hand.
I’m taking it off today and bringing it home for disassembly. I will get pictures and post.
I just got a boost gauge hooked up on the troublesome engine and found under load at 1800 rpm only one pound of boost! Removal of aftercooler and disassembly is next. Please comment if any of you have had similar problems.
Thanks
Hi Brad
I remember seeing one on youtube a guy did on a 6bta, really neat but simple design. Just search 6bta fresh water flush and you should see it. If I recall correctly he removed a plug on the sea water pump and piped up his inlet with valve in to the pump.
Good Luck
Forgot to mention that this was not an all of a sudden occurrence. The low power/rpm problem was present when I got the boat 1 year ago.
Tony,
I trust your guidance and appreciate the help and of course I will service both aftercoolers, they were on my agenda for this winter when I’m not using the boat but I think I will at least get the port done sooner. Your last post made a lot of sense and the aneroid pressure effect on fuel volume. Do the diaphragms in the aneroid ever need replacement?
Thanks again for your help
Hi Bill,
If the aftercooler is plugged I think that would result in the engine sucking hot air and reducing HP but would that cause it to be ok up to 1800 RPM and no more? There are plenty of engines around that run without aftercoolers at lower HP.
I’ll test the intake temperature on both engines with my IR tester and see if there is a big difference. Anyone know what optimal temperature reading would be?
Thanks
Tony,
Will do, obviously this will take some time and a big project for me (I’m 72). What’s your thought process on the problem and what are we trying to resolve with the aftercoolers other than good maintenance? I already checked the boost line between the aneroid and the intake manifold and it was clear.
No black smoke present.
Thanks again for your help.
The starboard test was a little easier initially, it’s a shorter hose than the port, about the same resistance after the initial blow. gurgling noise present at both tests. No fuel or drips present for both when hose was disconnected.
Hey Tony,
I blew thru the port (problem) engine fuel return hose and it was real hard at first like it was restricted but may have just been overcoming resistance to fuel in the line. Once that was cleared still not real easy to blow thru and made gurgling sounds as I blew. I did not do the starboard engine yet for comparison but will try and get it today.
Here are some photos of the starboard engine pump and after cooler and one of the port engine from above.
No maintenance history on the after coolers only that they have spent their life in fresh water. Looked clean when I drained them last fall to winterize.
Thanks for your input, running gear is fine and works perfect up to 1800 RPM. No vibration or problems associated with shaft, seals and props.
Tony,
The parts manual for the engines shows the following:
Base fuel pump option fp97220
Part # 3919762
Remarks
Nippondenso “EP9” type (non certified) boost control fuel pump for 300 BHP turbocharged seawater aftercooled b Series engine at 2800 RPM high output rating for 6BTA5.9 M2 engine. Has manual actuate to run fuel solenoid and 2.0mm tubing. Reference: CPL #0970 with FR9647.
I will try and get some photos although very confined area so I’ll have to break in sections. I have seen identical engines for sale on line. As far as boost goes, I have not checked. I’ll have do some reading on “how to”.
I will check the fuel return line to make sure it is clear. Aftercoolers are the same as the last one pictured on your aftercooler types tip. I will get details on it and reply. It’s the one with the rounded front made in Great Britain.
Engine info says series 403 if that’s of use.
Thanks for your help!
