Engine Stalling 3GM30F

Feb 27, 2004
172
Hunter 335 North East, MD
So, we went out yesterday in my Hunter 33.5 with the 3 GM30F yanmar and because I wanted to sail further down the Bay, I decided to motor sail to a different location. I was on starboard tack with a slight heel (fuel tank is on port about 3/4 full fuel filters and fuel lines are on starboard) and after about 25 minutes the engine just shuts down like its starved of fuel. I was unsuccessful bleeding everything out on the bay so I sailed back to my slip- changed both filters, bled the system and it still wouldn't start. I took the air filter off and it started right up- I ran it for awhile at different rpms and in gear and out and seemed to be ok. Put air filter back on and it started up again.

My question could the heel of the boat somehow caused air to get into the system? The shutdown didn't seem like a dirt in fuel line scenario. I did find water and some particles in the primary filter (Racor) but the secondary seemed clean- any ideas ?
 
Jan 4, 2006
6,444
Hunter 310 West Vancouver, B.C.
I took the air filter off and it started right up- I ran it for awhile at different rpms and in gear and out and seemed to be ok.
What was the condition of the air filter ................. clean or dirty ?

From what you describe, it would seem the problem was in some way related to the air filter.
 
Oct 22, 2014
20,992
CAL 35 Cruiser #21 moored EVERETT WA
Sounds like one of the three components of running the Diesel engine somehow was not there.
  1. Air
  2. Clean fuel
  3. Compression
You opened up the air path and you started and ran.

Is air filter clean?
Did the fuel filters look dirty?
70E2EEEF-770A-412E-913C-306346EAB7A1.jpeg

A dirty filter due to fouled fuel.

If you see bubbles in the fuel filter bowl than you have an air leak between the tank and or on the fuel filter. Happens occasionally when you change the filter or bleed the fuel Lines and do not get them properly resealed.

sounds to me like you successfully resolved the issue. Well done!
 
Jan 4, 2006
6,444
Hunter 310 West Vancouver, B.C.
sounds to me like you successfully resolved the issue
But ........................ what was the issue :mad: ?

The "WHAT" is the most important part. Without knowing the "WHAT", what do we inspect and repair ?

Oh God, where the hell is that second cup of coffee ?
 
Nov 6, 2006
9,884
Hunter 34 Mandeville Louisiana
Could be a cranking time issue where the cranking that was done before air cleaner removal had kinda primed the system.. Since it started and ran with the filter on after that, it may not have anything to do with the air filter.. Lots of times, the Yanmar air filters are fairly free flowing!
Yanmar Air Filter.JPG
 
Oct 22, 2014
20,992
CAL 35 Cruiser #21 moored EVERETT WA
Yes Ralph, What is the “What”? He changed the fuel filters. Good start. Tested the start after bleeding fuel lines. No start. Then removed the air filter. Engine Start.

Was it lack of air?
Did the fuel finally start to flow?

What solved the issue?
 
Feb 27, 2004
172
Hunter 335 North East, MD
I am going to clean the air filter, but I am curious to the primary cause of the engine shut down? Did the heel of the boat cause air to get into the line somehow or perhaps crud in the tank was stirred up or something else. In the past when I have had a clogged filter the engine struggled at higher revs but was able to sputter along at lower revs- this just lost revs quickly and died
 

RoyS

.
Jun 3, 2012
1,739
Hunter 33 Steamboat Wharf, Hull, MA
Where on the tank is the fuel pickup located? Is it possible that it inhaled some air instead of fuel on that tack? Fuel pickup should be near the tank center.
 
Feb 27, 2004
172
Hunter 335 North East, MD
Where on the tank is the fuel pickup located? Is it possible that it inhaled some air instead of fuel on that tack? Fuel pickup should be near the tank center.
Good question-the hose from the tank going to the primary filter is on the outboard or port side of the tank so it would have been lower than the fuel filter on the high side of the boat maybe
 
Jul 5, 2011
702
Oday 28 Madison, CT
Fuel pump strainer/fine filter checked and cleaned? Fuel tank vent line free of bugs or other blockage? Fuel pump power leads tight and not corroded?
 
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Feb 27, 2004
172
Hunter 335 North East, MD
Except for the manual lift pump there is no electric fuel pump on the engine- will check the fuel vent line - as a note I did take the boat out yesterday and ran it hard for 90 minutes and it ran like a sewing machine-- so I'll probably not track down the cause- thanks to everyone for their input
 
Jul 5, 2011
702
Oday 28 Madison, CT
Yep, the manual lift pump was where I had the intermittent short. Briefly in the CT River, then it came back on and later down for longer in a pond full of moored boats. Just a sill loose connection for me.
 

NYSail

.
Jan 6, 2006
3,048
Beneteau 423 Mt. Sinai, NY
The yanmar stock fuel pump is a cam driven pump. No electric. Once engine starts no need for electric to run….. all compression.

FYI….. inside the fuel pump is a screen. Last boat had a 3HM35f….. pump was leaking fuel into engine so replaced with a new one. I took the old one apart and the internal screen was dirty.

good luck
Greg
 
Feb 27, 2004
172
Hunter 335 North East, MD
SO that makes sense to clean the screen which I had no idea there was one- I have attached a diagram of the lift pump and I don't see a screen what am I missing - Thanks for your help
 

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Jul 5, 2011
702
Oday 28 Madison, CT
Sorry....That is completely different that the Fasco electric with a ratchet off bottom containing fine sieve.
 

Guan

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Jul 18, 2011
138
Beneteau Oceanis 361 Vancouver
I had same problem with engine stalling after three years of normal function following purchased of 10 year boat.
mechanics replaced all parts of fuel system and even injectors. but problem is intermittent and especially after a day's sail. stalled in middle of channel twice.
guys from our forum keep advicing fuel checks but the techs says it's ok.
finally I open the fuel thank and found a piece of rotting metal from a fuel gauge and polished the fuel.
So listen to all great personal info here.
 
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Dec 19, 2006
5,809
Hunter 36 Punta Gorda
I had gunk in my fuel tank and after running hour or more engine would die changed fuel filter
and run again for engine or more so took fuel gauge sender and fuel pickup w it’s screen on end of
pickup tube coated with crud and so what was happening when running engine and boat bouncing around crud would break loose and collect on screen cutting off fuel.
I pumped out all fuel in tank into jugs and put cellphone snake type camera finding more chunks of crud on bottom,used shop vac with hose down into tank and check with camera until completely clean and ran old fuel through fuel 2 Racor filters back into tank been running great no problems and been adding bio additives ever since.