Anyone have a good guide for bleeding the injectors

Steve Dion · May 4, 2012

I have been told to leave the high pressure part of the diesel fuel system alone and have a professional do it.

So my advice to you is to get a mechanic (that can be trusted) and have them spend an hour on your problem.

Benny17441 · May 4, 2012

Are you having problems starting the engine or is it running rough? What you actually bleed is the injector pump and you will find a bleed screw in its body.

sailaway78 · May 4, 2012

Bleeding injectors

You only need to bleed the high pressure side IF you have air in the system. Otherwise, leave it alone. Bleeding is pretty easy if needed. Just crack the nuts where the fuel line attaches to the injector, open the compression release, and crank the engine over for a few seconds. Be sure to turn off the raw water intake. I have done mine a few times over the years, and usually spin the engine, with all compression releases open, for 20 to 30 seconds. Gets the job done every time. Then just tighten the nuts back down and your good to go.

Tejas · May 4, 2012

A handy book on marine diesel engines that includes the answer to your question is "Troubleshooting Marine Diesels" by Peter Compton. Nigel Calder's "Marine Diesel Engines" is far more detailed. I refer to Compton's book first.

Bill Roosa · May 4, 2012

You only bleed the low pressure tank to injector pump side of the system. Once air gets past the injector pump the fuel behind it pushes it through the high pressure side till it exit through the injectors
The guy that told you to bleed the high side is not very knowledgable, consider getting someone else to help you on engine matters.

With that said; What is the problem? Perhaps the fine folks here can give you better advice.

Stu Jackson · May 4, 2012

paiscool said:
I have a Westerbeke 30B and I was told to bleed my injectors to see if I am getting fuel.The operators manuals I have show the injectors but dont show how to bleed them. Does anyone have a guide,(maybe with pictures) of how to bleed them. I dont want to take a possible minor problem and make it a major one because I am guessing what to do.
Thanks

I agree with Steve, don't mess with the high pressure side. Many of the return comments to your questions are from folks who may not be familiar with W or Universal engines, which are very diferent than their Yanmar contemporaries.

www.marinedieseldict.com should become your friend.

I did a little searching there and came across these:

http://shop.torresen.com/ships_stor...leed+Valve+Assembly&sectionid=Universal Parts

and

http://www.marinedieseldirect.com/c...ting for that engine in the table of contents.

The later Universal M35 engines (I know, I know, you have a W not a U, but bear with me) are self bleeding. But other Universal engines have BLEED SCREWS, a knurled knob, which when opened with the fuel lift pump operating, serves to bleed the system WITHOUT MESSING AROUND WITH INJECTORS at all.

That website used to have "Instructions to Bleed" at least for my M25 U engine. You may be able to find that for yours. If not, get the manual, pretty reasonable for your specific engine = what's it worth to you.

If it was my boat and my engine, I would NOT mess with the injectors until I assured myself that it wasn't something as easy as a bloody bleed screw, right?

Look at part #38, "Screw, bleed..."

Good luck, don't mix U or W engines, but also don't figure Yanmar ideas work for W or U engines, either, with all the well-intentioned suggestions, they do mean well.

Stu

RAD · May 5, 2012

On my old Westerbeke W30 there's a whole complicated procedure for bleeding the fuel system but if you read the WHOLE manual there's also a simple bleed procedure if your just changing the engine fuel system or messing with any fuel item before the high pressure system which is probably the case with most

zeehag · May 5, 2012

online find a workshop manual for your engine-is grouped with the 4-107 and 4-108, also--is a good reference.

kenn · May 5, 2012

This is from my brief time working with my mechanic mentor:

For normal spring commissioning, after changing primary and secondary fuel filters, it's usually only necessary to bleed just past the secondary filter, where most diesels have -surprise- a bleed screw.After this we found the engine would catch and run after a few seconds of cranking.

I do recall that opening the high-pressure fuel lines at the injectors is sometimes done as a diagnostic tool - it confirms the presence of fuel pressure to each injector, and it can be done to selectively 'disable' each injector while the engine runs.

The service manual is of course to be taken as the last word on this topic.

The third page of this bulletin set from a Yanmar dealer describes bleeding and includes cracking the injector side of the high pressure lines, but again we never did so for normal bleeding.

[edit] - found it - This version of Westerbeke owners manual which includes the 30B says that after filter change, you simply turn the panel key switch to ON and the electric fuel pump should do the bleeding in about a minute, without having to open any bleed screw or injector. Pages 17-21

Geoff K · May 5, 2012

Apparently electric fuel pumps move enough fuel so bleeding is not necessary? (at least that's the way it is on my Kubota lawn mower and tractor.) Can any diesel be converted to an electric fuel pump? If so, will bleeding be simply a matter of running the fuel pump for a minute or so? (If my Kubota runs out of fuel it starts within 20 seconds of cranking.)

Geoff

RAD · May 6, 2012

paiscool said:
The problem is it wont start.Will turn over.Replaced the 12 Fuel pump,Replaced the fuel filter.I hear it click when the key is turned on but still wont start.There is fuel in the new filter bowl so I have to assume fuel is to that point.After that point the fuel goes to the injector pump.That is why I thought I should bleed the injectors.Guess it is time for a mechanic though they seem to be in short supply here in the Dallas area where my boat is.

Did you bleed it after changing fuel filter??? and if not and cranked it over you now have air through out the fuel system I'm sure......all you need to do is read the manual how to bleed the system and it should take no time to do

Stu Jackson · May 6, 2012

paiscool said:
Guess it is time for a mechanic though they seem to be in short supply here in the Dallas area where my boat is.

I'm confused. Kenn provided you with the whole engine manual for your diesel. I read it. It says the engine is self bleeding. What is a "mechanic" gonna tell you that the manual hasn't already described?

OK, OK, if it still won't start and you HAVE read the manual, have you tried playing with the bleed screw? My M25 engine requires that the bleed screw be opened for a short period of time with the electric fuel pump ON. The clicking of the fuel pump is rapid, then you slowly close the bleed screw, and the clicking slows down - very evident. If the clicking remains rapid, there's still air in the lines, so do it over again until all the air is out.

The M25XP is essentially the same engine, but is self bleeding.

If this doesn't work for you, then I suggest you go to to the C320 Association website and ask there, or just do a search there on "bleeding" and I'll bet you get an answer almost immediately. www.Catalina320.com, most likely.

Good luck.

PS IMPORTANT!!! Have you opened up the fuel shutoff valve after you changed the filters???? Believe me, I've forgotten to do that myself, and will actually admit it!

PPS - http://groups.google.com/group/c320...cf9b4?lnk=gst&q=bleeding+30B#e5cd512ec94cf9b4

This thread talks about a faulty fuel pump, which could be possible in your case.

In addition, how is your fuel plumbed? Many Catalinas, if not all, came from the factory with the fuel pump first after the tank, then to the Racor, then to the engine. What happens is that the tiny filter at the base of the pump gets clogged up. If you have the metal Facet pump, simply remove the bottom of the pump with a ratchet/socket wrench and check that filter. Then, correct the plumbing to: tank, Racor, then fuel pump, then engine.

PPPS - If you have changed the secondary filter (on the engine) you most likely have to open up the screw on the bracket that holds that filter to assure air is completely out of that new filter, because the bleed screw doesn't work for that secondary filter. At least it doesn't on my engine. Try that, too.

PPPPS - Your engine has the what is crazy to me electrical arrangement where the fuel pump only runs when the glow plugs are on or if the oil pressure is "made." This means that having the key switch ON will NOT run the fuel pump. So you either need to hold in the glow plug button or key position to run the pump or you have to rewire the fuel pump to run when you want it to. I've discussed this on our C34 Forum, since the M35 engines in our boats are self bleeding, too, but one of our skippers raised this very question: http://c34.org/bbs/index.php/topic,5078.30.html