Engine runs 10 minutes then stops

[botanybay]

Another "trick" I use is to temporarily put a piece of clear tubing in the return fuel line. I use a loop where the top of the loop is above the rest of the system. Great way to determine if you have an air leak.

Unfortunately there is no approved fuel line which is clear that I have found. So it has to come out when you finish debugging the system.

[sailormed]

I have not read the entire thread, so maybe this has already been mentioned.
1. Check the primary fuel filter at the build in ball valve for crud.
2. Check the 90° bend of the incoming fuel line at the filter where it turms from upstream to horizontal. Crud often gets clogged in this bend.

[hasse_A]

I had the same problem with my Yanmar 3GM30F.
I filled a 4 L jerry can and attached it to the input of the boostpump.
Then the engine ran for hours. I had to top up the jerry can as excess fuel went back to the main fuel tank.
This convinced me that everything from the boost pump to the high pressure pump did not have any air leak.
I then studied the hose from the tank to the boost pump and detected some dry cracks. Replaced the hose and this fixed it,

[le chat beaute]

I venture to guess it may be contaminated fuel. The replacement of fuel filters has filtered out the bad fuel in the tank and are now loaded. When you bleed the system on a 3gm30 you will get about 10 minutes running time at 1800 rpm’s. Try by passing filter with a rubber hose and pick up fuel from a clean container. 5 gallon Jerry would work well. If the razors you installed are the smaller ones most likely the source of frustration.

[argonauta1]

Another possibility is progressive failure of the drain plug on the lower side of the Racor filter.

My experience: Midnight and approaching a headland I decided to motor sail around it as we were already close hauled. Fired up the trusty Yanmar four banger only to have it quit after 30 seconds. Reversed course and began fault analysis.

Fumbling around next to the Racor, head mounted flashlight bobbing around I happened to notice one air bubble rising inside the Racor glass bowl. Turned the knurled nob on the Racor and it came off in my hand. Cascading diesel. Plugged same with finger and called first mate to get me an ear plug, a large pop rivet and some marine sealant. Inserted ear plug over pop rivet and sealed all with 2600. Gave it a few minutes then reprimed and away she went.

Kept this lash up in place for a couple of weeks until I could buy a new Racor bowl assembly. Kept another ear plug in a small bottle filled with diesel to ensure ear plug did not combine with the diesel. It did not.

[svfinlandia]

Originally Posted by hasse_A

I had the same problem with my Yanmar 3GM30F.
I filled a 4 L jerry can and attached it to the input of the boostpump.
Then the engine ran for hours. I had to top up the jerry can as excess fuel went back to the main fuel tank.
This convinced me that everything from the boost pump to the high pressure pump did not have any air leak.
I then studied the hose from the tank to the boost pump and detected some dry cracks. Replaced the hose and this fixed it,

I don’t think that is his problem since he says the bowl on his fuel filter is emptying and then the engine dies. It sounds like a clog before or internal to the fuel filter.
To the OP: Please let us know what you find. I am still betting on the cloged check valve in the Racor filter.

Al, S/V Finlandia

[Stu Jackson]

Fuel Starvation and The Obscure Check Ball Valve
https://c34.org/bbs/index.php/topic,10681.0.html
and
https://forums.sailboatowners.com/th...l%20Starvation

[svfinlandia]

Originally Posted by Stu Jackson

Fuel Starvation and The Obscure Check Ball Valve
https://c34.org/bbs/index.php/topic,10681.0.html
and
https://forums.sailboatowners.com/th...l%20Starvation

As I said above, I had the same problem Stu.
I think that we have hit up on the OP’s problem.
I hope he reports back and lets us know what he found.

Al, S/V Finlandia

[hasse_A]

Originally Posted by svfinlandia

I don’t think that is his problem since he says the bowl on his fuel filter is emptying and then the engine dies. It sounds like a clog before or internal to the fuel filter.
To the OP: Please let us know what you find. I am still betting on the cloged check valve in the Racor filter.

Al, S/V Finlandia

Hmmm, the bowl in the fuel filer is emptying as you say. Then if there is a clog in the fuel filer or the fuel line before it, how does the air get inside ?

[svfinlandia]

Originally Posted by hasse_A

Hmmm, the bowl in the fuel filer is emptying as you say. Then if there is a clog in the fuel filer or the fuel line before it, how does the air get inside ?

harr! Good question!
If my theory is correct, then he must have an air leak into the filter somewhere also.

Al, S/V Finlandia

[skipperpete]

The GM series are practically unique in being just about the only engine with no return line from the injector pump or pressure side of the supply, just an independent leakoff line from the injectors so in the event of even a tiny amount of air inbound on the suction side there’s no permanent bleed off to purge it and it accumulates until the engine stops.

[Looking4Neptune]

Like Mathis, I'd look at the fuel shutoff valve that shuts down when the temperature goes too high. If this is the problem, your coolant system is faulty. First check would be the impeller.

But you did say you were able to run 25 minutes when bypassing the fuel filter, so that would argue against this idea.

Good luck!