[CS_dave]

I have a Westerbeke 30 (formerly called Four-91) 4-cylinder diesel engine in my CS36. I bought the boat two years ago and maintenance records indicate that a top-end rebuild was done about 2 years before I bought it. The motor worked great the first season, other than a plugged heat exchanger full of algae and barnacles from sitting for 2+ years.

I replaced both the fuel filter / water separator AND the secondary fuel filter just upstream of the injector pump as well as changed all the fluid and belts, oil filter, etc. New starting battery.

The following spring (last year) the engine would not start first time out. It would crank and crank and crank and crank but no coughs, no nothing. I figured I must have air some place and systematically bled the whole system. Voila, started right up.

So the same thing happened this spring. And I used the same fix. Again, engine running. However, two weeks later I had the same symtoms, pretty much. When I first push the starter (after running glowplugs ~30s) it sounded like it was on its' way to starting, periodically coughing, catching, dying. After about 10s of cranking, the coughs and puffs of smoke abruptly ended... sounded like it was getting zero fuel. At this point I'm frustrated... we're loaded up to catch the tide, and my wife has "how long is this going to take?" on the tip of her tongue. So I cracked all four injectors, cranked for 10 or 15s, tightened them back up and it started right up.

Any guesses as to what could be causing this? Visibly, it's tough to tell if I have a fuel leak as the engine does drip a fair bit of oil. Even after prolonged running of 4 or 5 hours, there's no smell of diesel so I surmise I don't have a leak on the high-pressure side.

Any suggestions greatly appreciated.

Dave
CS36 - dolce fa niente

 

[jimrafford]

You obviously have an air leak on the low pressure side of the fuel system.
My 36t developed the same symptoms several years back. Turned out to be one of the seals on the top of one of the filters wasn't seated properly. I would also check the seals on the low pressure fuel pump. That would be leaking into your crankcase.
Jim

 

[christian.hess]

bingo....check all your low pressure hoses and piping including banjo bolts and such...

if it starts right up after a quick bleed you know your answer...

 

[jameswilson29]

My best guesses:

Have you checked your oil? Is there a smell of diesel fuel in the oil? (Could be the cause of the dripping oil - it has been thinned by fuel). Might be a leaking diaphragm in the fuel pump, if you have that type of pump. My engine has to be on half throttle or higher to start, so you might have a fuel deficiency at start up. Might be bad fuel. Might be leak at secondary fuel filter - it is challenging to properly re-assemble those suckers, after changing the filter. Mine has 4 different o-rings, one each at top and bottom of filter, on on the center pipe and one on the bleed screw, and I have to hold it just right to reinstall it. After a filter change, I wipe off the filter carefully so it is dry, start the engine, then run my hand around the secondary fuel filter to make sure there are no leaks.

It is cranking, so we know it is not a battery, electrical connection, solenoid or starter issue.

The test for a low pressure fuel system problem is to unscrew the bleed screw from the secondary fuel filter and turn the engine over using the starter.* Does airless fuel spurt out of the secondary fuel filter? (*from recommended diagnostic manual below.)

Farther down the line, you could check that fuel is reaching the injectors by loosening the injector supply lines, again turn over the engine using the starter, and check for fuel spurting out of the injector supply line*.(*from recommended diagnostic manual below.)

A step farther down the line, you can check the injectors by disconnecting the return line, removing the injectors, and checking the spray pattern from the injectors*.(*from recommended diagnostic manual below.)

You might also check the glow plugs to make sure they are properly heating up - that might explain why you have greater problems starting in colder weather, but it starts o.k. in the summer.

Are you sure your engine is not self-bleeding?

I suggest you buy a good diagnostic manual and run through each step for a cold start up problem. I recommend *Peter Compton's "Troubleshooting Marine Diesels". No one can accurately diagnose your starting problem from a distance. You must work through each system step by step through the process of elimination to locate the problem to be repaired.

 

[CS_dave]

bingo....check all your low pressure hoses and piping including banjo bolts and such...

if it starts right up after a quick bleed you know your answer...

Thinking back, the issue seemed to start when I replaced the secondary filter right after buying the boat. I was subsequently told by several diesel mechanics that I didn't need to do the secondary every season unless I routinely used dirty fuel or had super-high hours. So I haven't replaced it since although there's one sitting on a shelf in my garage. I have replaced the fuel/water separator/primary filter several times over the past few years.

My parts manual lists two repair kits for the lift pump (major and minor) but they are long since out of production, hope it's not the lift pump. I changed the oil this spring and it did not look at all thin, nor was there a noticeable smell of diesel so hopefully there's nothing wrong with the lift pump itself.

I will bite the bullet and disassemble the whole low-pressure side, carefully check o-rings, crush washers and filter seals and reassemble.

Thanks for everybody's input. Dave

 

[christian.hess]

you know...sometimes on some engines adding a secondary filtering system causes all sorts of issues...one of which is low flow if you will...sometimes people add an eletric pump and or take off the filter all together...

I always filtered(manually) my fuel before dumping in the talk(thats if your tank is known to be clean)

a lot of times its the secondary filter that when not seated right especially the big orings and or lower ones on the bowl that under suction will leak air...causing you to have to bleed it all he time after some sitting

try bypassing this filter to see if this is so....or make darn sure its in perfect sealed condition

ditto on all the washers, orings, banjos etc...

on crush rings in the moment you can reuse them once or twice by flipping them over and getting a new "SEAL" if you will but its just better to get new ones

good luck