6BT5.9M excessive cranking

[H Frank B.]

My port 1988 vintage 6BT5.9M has an intermittent starting problem. On occasion I find myself cranking for 20 – 30 sec. and after 2 or 3 or …cycles it may start. I will get the marina tech. to get into this next spring ….. ( fuel and filters are new and clean ) but what are the risks of this excessive cranking with the ” raw water sea cocks OPEN ?
I read somewhere that water could get into the engine .. ??? Thank you in advance for any comments … FB

Topic

[Tony Athens]

Frank,

Clark is going the extra mile to help………………Help him and the rest of us looking to help you..
Trust me, it does not get any better, but YOU have to help us , or Clark in particular, to help you..

He has taken this on, so give him the chance………………………….Do what he is asking………………..

Tony

[Clark Leighs]

Frank,
Rereading made me look at your fuel system description a bit more. Does the generator feed from the same manifold as the engines after the filters. You would not be the first to have air in the engine fuel system due to a generator feed where it should not be. That hook up is easy and that’s why folk do it. But it can backfire sometimes with the generator line being the air leak source.

[Clark Leighs]

Have you made any progress??

What have you done to troubleshoot the starting issue?

How do you prime the system?

Got the photos?
Answer Tony’s questions and do as he asks and you will get help.

Have you really rebuilt the Racors? There are some catches to those filters, good a s they may be, that can cause trouble.

Forget the electric pumps until you solve the starting issue. All you will do is complicate the whole issue.

Most starting issues like you describe is air getting into the system. Loose connections, leaking seals in the filters,

failing hoses, failing lift pump which can be fixed.

Each time you get the engine running and then shutdown an air leak will allow the fuel to drain back to the tank. At least drain away from the injection pump. Then it must pull fuel again which takes time and a bunch of cranking.

It could be something else but that is a start.

Fix the real problem.

Some info from you may help us help you.

I´ll point out that there are millions of engines running around successfully without electric pumps used as you describe.

Not to be mean but just to get the point across that what you are asking about is not a fix.

[Tony Athens]

Frank,

You are asking for a good response but I have nothing to give or offer.. Why you ask?

Because you have not sent me anything that I need to help me help you since my 1st response over a month ago….

Asking for “band-aid” like an electric fuel pump will not be your answer if you want to solve your issue…

I am here to help, but I need help too..

Tony

[H Frank B.]

Thank you again for your reply Tony,
The boat is currently on the hard in heated storage. Re: exhaust, the muffler is down and about 16″ + below the raw water engine discharge point Re: starting issues, I have elected to replace the lift pump on ” that ” engine and will see what happens after we launch in the spring.

The fuel plumbing is as follows: Two tanks ( looks like gravity feed ) feeding into a common manifold where it splits into each Raycor ( and also Gen.,) then it’s plumbed to each engine lift pump, then to the last chance filter on engine and then I assume ? to the Hi press. pump.
I also want to install electric fuel pumps for each engine, I intend to install them after the large Raycors ( before the lift pump ) and will wire them to the ignition switches ( maybe ?? with another parallel switch to help purge after filter changes ) .

Q1 – Is this the way to go ? am I on the right track here ?
Q2 – If so, can you recommend a proper / quality electric fuel pump that will put out the correct pressure and
will allow flow through IF this pump is not used ?

Thank you in advance … Frank B.

[H Frank B.]

Thank you … I will take photos next time I’m up …. HFB

[Tony Athens]

H Frank B,

If your engine needs that type of cranking before it starts, then you better listen if you really want to fix this issue..

No start = no fuel, no heat ( lack of compression) , or a combo of both, PLUS possible major issues concerning the exhaust design……

Your call , but if I were you and came here for help, I’d get a good camera and post good pictures of the installation from all angles & perspectives showing all… ..

Understand, we are not trying to sell you anything here, just trying to save you the BIG BUCKS by offering the advise you need..

Tony

[Rob Schepis]

Impossible to answer without the specifics of or pictures of YOUR exhaust setup. Excessive cranking can fill a water lift muffler..

[Chris Dahl]

If your exhaust and mixer is built just right (meaning wrong) your raw water pump fills the exhaust while cranking (because the cranking pumps water) and you have no exhaust to push water out the tail pipe so you can get water flowing back into the turbo, which can be real damaging to your wallet.

[Author]

Replies