6BTA 5.9 SWAC 330 HP stops suddenly

[David Jansen]

Help! I am baffled. I have a 2004 Monk 36 with a Cummins 6BTA-5.9-M3 SWAC 330 HP, 2788 hours. It’s been pretty much flawless.

In October I left Maine for warmer winter climates. Five weeks later after a slowish trip (cruise 1800-2000 RPM) of 162 hours, I reached Charleston, SC. A couple days ago, when I started the engine and readied to weigh anchor, engine stopped very quickly, no run on. Started right away when I hit the start.  Few minutes later it stopped again (I watch the solenoid shut off). Started up right away. Once under way it ran fine. This has happened a couple times. I’ve tested this at the dock – same thing.

Fresh Racor and on engine fuel filters, no obvious things amiss. Checked the wiring – all looking fine.

What are your thoughts, oh Sage? Solenoid going?

Thank you for your help.

Topic

[Tony Athens]

wire crimpers

My personal favorite.. Klein 1005’s

[Rob Schepis]

Here’s a better link to those crimpers, the link in my above post I did from my phone and now see it was not a good source

https://www.google.com/search?q=OTC+5912&rlz=1C1GCEU_enUS916US916&oq=OTC+5912&aqs=chrome..69i57j0i390l5j69i61l2.2542j0j15&sourceid=chrome&ie=UTF-8

[Rob Schepis]

Thanks for the follow up.  I personally don’t like any of those rachet type or fancy crimpers. I prefer a high quality simple crimp tool where you are always in full control and get the direct feedback as to crimp pressure etc. i prefer these right angle pliers as they provide great access and full view of your crimp while in the making.

OTC 5912 CrimpWell Angled Wire Crimper

https://a.co/d/6yuFrbV

1 user thanked author for this post.

Tony Athens

[David Jansen]

all fixed

When I re-terminaled the wires to the 10A breaker, I used some new Anchor heat shrink terminals. I crimped them with an Anchor ratchet crimper. The wires felt snug but a couple weeks ago I redid the ends with non-heat shrink ring terminals.

At this time, and for the past ten days, I have not experienced the shutdown. Digging into the Anchor stuff, I was told there is a different crimper for the heat shrink terminals.

Lesson learned.

Thanks again for the help.

Dave

[Francis Valerio]

on my previous post to be clear I mean the fuel shut off solenoid is the ONLY thing “ELECTRICAL” that can cause your engine to shut down…

[Francis Valerio]

Like Tony said, the fuel on/off solenoid is the ONLY thing on this “otherwise” mechanical engine that can cause it to shut down.

By tying the solenoid in the “up” position it will either CONFIRM or RULE OUT an electrical problem as the cause of your “sudden” shutdown issue.

 

 

 

[Clark Leighs]

Rob circled a plug that supplies power to the shutdown  solenoid.      Check it and be sure the contacts ,  plug and receptacle make good, solid contact   when secured the plug is snug in place.

I don’t know what kind of plug it is but if possible check that the wires in the clamps inside the plug AND the receptacle housing are snug and the wires are in place properly.    Any looseness or poor contacts can cause a momentary voltage loss or V drop which may cause the solenoid to drop out.

 

[Rob Schepis]

Do you notice anything erratic at the instrument panel voltmeter just before or when the engine shuts down?

To aid in Tony’s troubleshooting post:

How the Cummins Bosch P7100 Injection Pump Solenoid Works

[Tony Athens]

NEXT STEP?

From what you have posted, this is an “electrical shut down” .. That means the mechanical fuel solenoid is losing  power to it ( falling out)   or it is defective in the run circuit coil and doing the same..

Only one way to confirm.. Pull up the solenoid and tie it in the fully retracted position.. The engine is now in the “no electricity needed mode” once started and will run until it runs out off fuel or you untie the solenoid linkage

Go fishing–If all is ok, then you need to sort out your electric system that operates it.

It’s all here on this web site

If this is above your pay grade,  get a good all around diesel mechanic to help you out.

[David Jansen]

I spoke too soon.

Hi Tony –

Just got back to the boat. Looks like the 10A breaker fix wasn’t the issue. I fired engine up yesterday and it shut down. Did that twice.

Today I also fired it up and shut down twice. It’s 58 degrees out.

Everything looks good – any other suggestions?

Thank you –

jansen

[David Jansen]

Spot on!

Good morning Tony –

It would have been nice of Cummins to make the wires to the circuit breaker a little longer. I cut the terminals, replaced with new ones, everything got dielectric. It appears your wizardry has once again shown itself. Engine started and ran without stopping. Did this a couple of times and all appears fixed.

Boat will sit here for a couple months (I’ve freshwater flushed the engine and genset) and I anticipate no more problems when I get back.

Thank you so much for your help and knowledge.

I’m flying to CA tomorrow (grandkiddies) but will be too far north to stop and buy you lunch.

Best –

jansen

[Tony Athens]

Loose wire under the RED circuit breaker next to the aftercooler–Frequent occurrence.. Redo do it all and add grease on the connections

[Author]

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