Not boosting

[jonathanschanter]

My port cummins 6cta 450 diamond would not boost on the way home last night.  Little history first.  The entire salt water cooling side was removed and cleaned last winter.  Antifreeze flush and new put in. Fresh belts and less then 25 hours on the new fuel filters. Also new gear case and gear case cooler in April.  Last Saturday I did a quick dive and cleaned the bottom which was very minimal but I did have to tighten the port prop a bit but I can’t see that effecting anything.  So we stayed on the hook all weekend.  The cove is only 3ish miles away from home port. I was towing my dingy so I trolled there about 1200rpm. Got there set the hook and didn’t move till Sunday night.  I started the motors about 15 minutes before we left and idled out of cove.  Got motors up to temp and went to take off.  Star motor spooled up perfectly but port motor wouldn’t get past 1500 and only about 2-4# of boost. Backed down and tried again.  Star motor spooled right up port motor again wouldn’t spool. Egt was about 300 and held.  I waited 15 or so seconds and nothing.  Backed down again and tried to bring up just the port motor to see if I hear the turbo spool and nothing 1400 rpm no boost and egt about 300. Zero smoke. Idled for about 10 minutes past the next no wake zone while my wife took the helm I went down and checked all the hoses everything was tight and in good condition.  Oil pressure was prefect and temps holding at 178. Came out of the no wake zone and tried again.  She jumped right up and both motors hummed along at 2250 17-18 # of boost and egt at 825 the whole rest of the ride home.. and ideas?

Topic

[Tony Athens]

At this point,  only really  good pictures of of the engine ( especially of the fuel injection pump) may give the forum a clue so we can all see what we are trying to deal with.

[Nathan Brady]

You said no black smoke on the engine that wouldn’t push up? Could your fuel shut off solenoid have been sticking or getting weak? I’ve seen them not fully actuate and limit the fuel causing low power and no black smoke. 

1 user thanked author for this post.

Tony Athens

[Rob Schepis]

If you need you can email pics to rob at sbmar.com and I will post.

<br />Prolonged cold idling of a diesel has bad long term effects (plenty of searchable reads or google on that) so wasn’t sure if that was your normal practice but it appears was an isolated incident.

<br />So no dark smoke, that leads to a fueling issue.

<br />So the starboard motor was as normal and so was the fuel level in the Racor but the port motor that struggled had low level in the Racor. I would not ignore that. Has the unit ever been broken down for a cleaning and rebuild? And I’d check the fuel lines from the Racors back to the tanks including the pickup tube.

Lots covered In the Lower Power Article in Tony’s Tips.

[jonathanschanter]

I dunno I tried paying several pictures with no luck…

[jonathanschanter]

And zero black smoke

[jonathanschanter]

• The prop I have no explanation for. I went for a dive to clean the bottom and grabbed the props and one was loose I really don’t have an explanation but it’s tight now..
• As for starting for 15 min before.  A buddy has a hard time pulling his anchor so I was sitting idle.. what’s wrong with starting 15 minutes prior?
• S for pictures I’ll get a few
• Few updates I pulled the filters racor and spin on and they were all spotless and still white.  The fuel level in the racors however was down about 3 inches in both genny and main racors and they pull off the same tank.  So far that’s all I found. 
•  

[Rob Schepis]

When you were trying to get the port motor up was there black smoke?

Post some good engine room pics showing both engine installs, turbos and exhaust included.

Also, I must say, both of these are concerning:

Tighten the port prop a bit?

Started the motor 15 minutes before you left?

 

[Author]

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