Official Cummins 6cta 450C thread

Thanks Mark. I figured that's a banjo bolt going through the square end of the curved pipe part. I can clearly see the crush washer between the square end and the priming pump. But I don't see a crush washer Between the bolt head and the square end.
 
Good morning all! Enjoying the heat?? Quick question. Does anyone have an idea as to why a diesel may just stall after coming off of plane for over an hour an running great? No alarms, started right back up and ran fine. Second time this happened. I'm new to diesels, so unfamiliar territory.
Thanks,
Mark

BTW...Cummins CTA 480's
 
Are your fuel filters clean? If you have dual Racors are you running in one or both? What about air filter condition?
 
Have you ruled out that your hand bumped the start switch? I've done that on mine. Put my hand on the switch panel without realizing it and inadvertently depressed the start switch to off.
 
Definitely did not bump the start switch. Fuel filters should be clean as they were just recently replaced. The "pressure" gage on the raycors show it to be ok. Not sure about the air filter. Will check though.
 
Definitely did not bump the start switch. Fuel filters should be clean as they were just recently replaced. The "pressure" gage on the raycors show it to be ok. Not sure about the air filter. Will check though.
I've removed the air filter for a short ride to test to rule it out or determine it was the culprit.
 
It should really be only one, (or both) of those type of issue, correct?
Diesel combustion triangle is air-fuel-fire. Since you were running fine on plane, we can rule out fire (pressure/heat). Leaves only air and/or fuel interruptions.
 
When you said they "should" be okay that makes me nervous... do you have the gauges on your racors that have an indicator showing the highest vacuum? If not, what vacuum are the running at when you are on plane?
 
Good morning all! Enjoying the heat?? Quick question. Does anyone have an idea as to why a diesel may just stall after coming off of plane for over an hour an running great? No alarms, started right back up and ran fine. Second time this happened. I'm new to diesels, so unfamiliar territory.
Thanks,
Mark

BTW...Cummins CTA 480's

This may be a case of what is commonly referred to as the CE stumble/stall. A 6 CTA mechanical will not do what you are describing.
I don't know a lot about it but the electronic controlled CE's can get a glitch in them that can be taken care of relatively easily but a tech has to do it as it requires a diagnostic patch. Your Cummins service man is your friend here (unfortunately).
If it were me, I would call Seaboard Marine, describe what's going on and see what they say. Please report back, diagnosing over the internet is iffy at best. I may be all wet.
 
When you said they "should" be okay that makes me nervous... do you have the gauges on your racors that have an indicator showing the highest vacuum? If not, what vacuum are the running at when you are on plane?

Yes I have the racors. The vacuum is pretty low.
 
I'm confused. I need to remove the elbow fitting attached to the big painted nut in the second picture. It slightly weeps fuel after turning off engine. We tried everything and we couldn't get it loose without fear of snapping the curved pipe. So I am going to remove the whole thing and put the nut in a vice. So I figure maybe I'll just replace it if I am removing it.

Well, the first picture shows the part callout on quickserve. Looks like I need a combination of items 2 and 3. And if it's really just a plug going into 2, then what's holding it onto the primer pump? In reality is it a banjo bolt and not a plug?

So I am not sure 1) how to remove the curved pipe/nut item and 2) what replacement part to order.
Just an update that I figured it out. My fuel pipe has a cubed banjo bolt end with a banjo bolt and two crush washers (picture 1). not cylindrical as in the drawing. That's irrelevant. So the replacement to buy is part #3, which is Cummins part number 3393767. Plus two new crush washers. They are just M14 copper washers which you can get online or at an auto parts store for almost nothing. Or $6 each from Cummins.

Also I found out part #2 is the adapter used on the fuel cooler. Mine has been removed as I replaced the fuel cooler with just a straight water hose (picture 2).
 

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Only get one click when hitting the ignition. Replaced the mag switch thinking that was the problem...still only one click. Not a battery issue. What's my next step?
 
Only get one click when hitting the ignition. Replaced the mag switch thinking that was the problem...still only one click. Not a battery issue. What's my next step?
You can check voltage in and out of the switch to be sure
I have jumped the mag switch when I didn’t have a spare... you can try that to be sure
Only thing left is the starter
 
You can check voltage in and out of the switch to be sure
I have jumped the mag switch when I didn’t have a spare... you can try that to be sure
Only thing left is the starter
Turned out being a loose wire to the 10 amp fuse on top of the engine. Played with some connections and started right up. Moral of the story...follow the Cummins troubleshooting guide. If you hear the starter try to engage with that loud single click, check all of your terminals and connections.
 
I had this all ready to send but you beat me to it....
You should also check your ground straps to engine...had the same thing happen to my mechanical cats. The eyelet wires were making an intermittent connection and would shut the engine down. This happened a few times before I figured it out.
 
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I finally got around to taking it off. Banjo bolt came loose pretty easy. Now to put the big nut in a vice and take off the hydraulic fitting.
 
I got it off. I had to put the wrench on the end. When I put it on the neck of the elbow it just rounded it off. I'm going to reuse the banjo and buy a new hydraulic elbow from the local hardware store.
 

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All cleaned up and repainted. Looks like I am going to have to reuse the hydraulic fitting elbow. Hopefully I didn't bang it up too bad. It appears to be 1/2" flare by 1/2" mnpt elbow and I can't find such a thing anywhere with the tapers mnpt threads the correct size. I'll try Ferguson here and see what they have.
 

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Starboard engine voltage is way high (15.5 V), increases with engine RPM. I verified with a multi meter on the battery. Are the alternators rebuildable, or would this be better off buying new?
 

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