Cummins 6bt starting issue

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May 3, 2014
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Hello all! I have a 35 Sportfisher with twin 6bt cummins turbo diesels with 1450 hours each. The starboard motor starts fine when cold but after I run her for about an hour, and turn her off, she will take upwards of ten seconds to start. I bought the boat at 1300 and the prior owner replaced the starter selenoid on that engine so I suspect it may have had a starter issue then but it doesn't show when cold so I didn't catch it during testing, nor did the survey. It went away and then came back after I changed the rancor fuel filters. It was great for about 30 days starting super fast and better than ever and now it's back again. The other motor doesn't do it otherwise is think dirty fuel tank. My mechanic can't seem to figure it out. I do run the stereo for an hour or so when I get out so it might be a reduced voltage issue since I first power up with shore power. I've started the generator for a few minutes before starting to maximize he voltage. The batteries test fine. There does not seem to be air in the system and since it's only when's ts already ran I can't find it. It can sit for four hours and it will still do it but then it's fine by the following Sat am. Boat is in sf. Happy to pay another mechanic come check it out.
 
So when you try to start, does starter engage and start spinning engine? Then take 10sec of cranking before it fires? Or 10sec before starter engages? Which engine is this? 6bt 210? 6bta 250, 270, 330, 370 etc. They have different injection systems.
 
Thanks for the reply. Yes, starter engages and then takes 10 seconds to crank, about 8 or 9 seconds in you can here the motor start kicking alive then boom it's on and runs fine. I'd say that motor has less power and runs 200 rpm less at wot if the boat is fully loaded with fuel and passengers. 1990 6bta turbo 330.
 
Air leak in the fuel supply. When the engine is stopped, air is getting in somewhere. Did you put new gaskets in the Racor? Did you use "the spacer?" Is there any sign of weeping fuel anywhere?
 
Thanks. new gaskets were used. I'll have my mechanic check further for air leaks. He still thinks it's the selenoid but it starts when cold so not sure how running it for an hour impacts the selenoid unless there is a voltage drop once off shore power for awhile which is going to be checked this week.
 
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May be irrelevant but a couple of years ago I had a problem starting my 6BTA5.9 after Winter storage. Motor cranked OK but would not start. Problem appeared to be the fuel solenoid. This is normally closed but if it was held open manually motor fired up OK. So went off to buy a new fuel solenoid at the Cummins truck stop. Fortunately, the Cummins shop tested the solenoid and declared it fine. Back to the boat and re-install the original solenoid. To make a long story short, problem was a tired 8D starter battery. Enough power to crank the engine but not enough volts to crank and open the solenoid at the same time. Check the voltage at the solenoid. Sounds like you might just have a related problem, assuming you have 2 starter batteries. Perhaps even if you have a single start battery could still be poor voltage at the problem solenoid.
 
on a 330 it is easy to check solenoid: Turn ign on (solenoid will not move), then bump starter. Pull in coil on solenoid is wired to starter, once bumped the solenoid should snap to the run position and stay there til ign is turned off. Easy check to do.

Does sound like air getting in to fuel supply, from somewhere.
 
Will check and report back! thanks!! It's driving me nuts trying to find it. It's weird that it starts fine when cold and not after an hour of run time,
 
I've been going nuts trying to get my 6BT started recently. The started would spin it but it wouldn't fire. I even gave it a shot of ether to see if it was a fuel problem. I had decided to do a compression test when my mechanic decided to put 24 volts to the starter. It started right up. It turned out to be a bad ground. Cleaned the ground contact and now she starts right up. The starter just wasn't spinning it fast enough.
 
Ski and other members: For my education, please explain why a fuel solenoid requiring power for the engine to run is better than one which only requiring power to stop the engine (like my Yanmars). At first glance the latter appears to be the better (fail-safe) option.
 
Ski and other members: For my education, please explain why a fuel solenoid requiring power for the engine to run is better than one which only requiring power to stop the engine (like my Yanmars). At first glance the latter appears to be the better (fail-safe) option.

I think most boat people would agree with you: better to have it "energize to stop". The reason Cat and Cummins engines usually use "energize to run" is that the engines are often spec'd for gennies and pumps and automotive, etc where ETR is preferred. Easier for a gennie auto shutdown to use ETR. So they probably use ETR across the board to simplify parts count.

Most engines do have kits available to set up either way. I've converted a few marine engines from ETR to ETS.
 
It takes more power to activate the solenoid from the stop position than it does to maintain its open fuel position. Once activated the power draw is less. I think it is relatively easy to activate manually and maintain in the open position with some "jerry rigging" (I hope this is not a derogatory term these days, no offense to German members intended!!).
 
Check to see if the fuel solenoid is getting full throw. You can disengage the arm and wire it open to see if that has any effect. Cut the wire when you want to shut her down and reconnect the throw arm.
 
I think it is relatively easy to activate manually and maintain in the open position with some "jerry rigging" (I hope this is not a derogatory term these days, no offense to German members intended!!).

If you stick to the 17th century nautical term "Jury Rigged" it's a lot safer and correctly reflects your meaning. Also the PC police won't come after you for the other term. Which it seems, is attributed to a number of different sources that are all offensive to somebody. But all believe it has some derogatory meaning! :facepalm:
 
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Run 2 thin temporary wires from the starter up to the bridge and watch the voltage with a digital meter when attempting both cold and warm starts.

You should have near 10V during the starter operation .
 
My apologies to all those members of German, (Mr. Edelweiss included??) or people called Jerry (not the mouse!!). I stand corrected and henceforth shall use the term "jury rigged" when referring to items constructed with ducting tape and baling line!!
Of course, I would still be interested to know if the solenoid was the cause of the problem and whether the jury rig helped!!

A jerry-rigged expression?


August 23rd, 2008
Q: Help me, Rhonda! I am so tired of coming across the term “jerry-rigged.” Writers great and small, learned and not so learned, constantly get this wrong. The term is either “jury-rigged,” referring to a makeshift emergency repair, or “jerry-built,” meaning thrown together with whatever’s handy. These terms are not the same.
A: I don’t think Rhonda will be of much help on this one.
The term “jerry-rigged” has already made it into both The American Heritage Dictionary of the English Language (4th ed.) and Merriam-Webster’s Collegiate Dictionary (11th ed.) – without any warning labels.
American Heritage says the verb “jerry-rig” is an alteration of “jury-rig” influenced by “jerry-build.” Merriam-Webster’s says the participial adjective “jerry-rigged” is probably a blend of “jury-rigged” and “jerry-built.” Thus language changes.
In fact, this “new” jury-rigged (or jerry-built) phrase isn’t all that new. It’s been with us for nearly half a century, according to Merriam-Webster’s, and means built in a crude or improvised manner.
Of the three expressions, “jury-rigged” is by far the oldest, with roots going back to the early 17th century, when a “jury-mast” was a temporary mast put up to replace one that was broken or carried away, according to the Oxford English Dictionary.
The earliest published reference in the OED for “jury-rigged” is in a 1788 travel book: “The ships to be jury rigged: that is, to have smaller masts, yards, and rigging, than would be required for actual service.”
The writer used the expression as a passive verb. To “jury-rig” now means to improvise or do something in a makeshift way.
The first citation for “jerry-built” is in an 1869 glossary: “Jerry-built, slightly, or unsubstantially built.” The origin of the expression is unknown, but it’s thought to be influenced by the use of the word “jerry” in English dialect to mean defective. The expression still refers to something that’s shoddily made.
The language sleuth Hugh Rawson, in his book Devious Derivations, lists eight of the more imaginative theories about the origin of “jerry-built,” including suggestions that “jerry” refers to the biblical walls of Jericho, the prophet Jeremiah, or German soldiers.
I’m not ready to use “jerry-rigged” myself, but with 56,000 hits on Google, it’s holding its own with “jerry-built” (79,000) and “jury-rigged” (123,000).
 
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I stand corrected and henceforth shall use the term "jury rigged" when referring to items constructed with ducting tape and baling line!!

Down in this part of the country we usually refer to it as "redneck engineering."
 
Here it's "buckshee" if it's temporary or shoddy and "skookum" if it's built to last.
 
I am sure there are a lot or rednecks on this site who are deeply offended!!!

Nope. They would take it as a compliment. (I come from a redneck background myself). For some fun photos google "redneck engineering."
 
My apologies to all those members of German, (Mr. Edelweiss included??) or people called Jerry (not the mouse!!). I stand corrected and henceforth shall use the term "jury rigged" when referring to items constructed with ducting tape and baling line!!
Of course, I would still be interested to know if the solenoid was the cause of the problem and whether the jury rig helped!!

Uhh I'm not offended, I'm Italian/English Canadian-American! :thumb:
The boat name "Edelweiss" is of German origin, I didn't pick it, but I like the flower, the German song (from the Sound of Music) and German food / beer in general. Prost!!

Your citation is right on. I don't believe the term "Jerry Rig" has anything to do with WW2 German soldiers, Jerry Lewis Telethon, or the Jerry Springer TV show, since it's use predates all these events. It's just another example of the English language evolving, which the PC police examines with a caustic eye looking for a victim. :angry:
 

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Nope. They would take it as a compliment. (I come from a redneck background myself). For some fun photos google "redneck engineering."

Let me clarify this, by the way, because I would not want anyone to come down to this part of the country and make an error (and possibly lose teeth) because of my comments. You do not call anyone a redneck, nor do you sneer at something and call it "redneck engineering." Sure way to lose teeth. But if you have the right accent, dress in jeans and a t-shirt, and see where Buddy Bob has built something really creative and ingenious, then admiring it and saying (with a smile) something like "Whoa! That is a great piece of redneck engineering!" would not be considered bad manners. No lost teeth.

Basic building blocks for projects are duct tape, baling wire, PVC pipe, rebar, and concrete blocks.
 
Some of us Carolina rednecks build boats, too. Some come out pretty nice. Our necks do get red sometimes (farming or fishing). And some of us have engineering degrees. So yep, "redneck engineering"!! No insult at all. Well, maybe, maybe not!! :rolleyes:
 
so what happened with the 6bt starting issue?
 
so what happened with the 6bt starting issue?

Well . . . it kind of got hijacked, I guess, and since I played a minor role in said hijacking I apologize.
 
Take care. A "jury rig" is very different to a "rigged jury" Some Australians will remember "Joh`s Jury". ("Joh" was a Queensland politician.)
Not unlike distinguishing between "a fallen woman" and a woman who has merely fallen over.
 
Just a thought on the Cummins 6BT, some of those engines had a fuel non return valve fitted and if the little spring is weak the fuel will run back making it hard to start.
If the electrical's on the starter are fine I'd have a wee look there to check it out.
 
Fuel Solenoid

I would think power to run is a better fail safe option than power to stop. It seems this could prevent a run away engine situation in the event of a failure of the solenoid after the engine was running. What am I missing?
 

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