J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Diesel problems

Finally the water is low enough in the resvoir and the marina figured out a way to hoist the mast without using the broken gin pole. But... I Went to launch and couldn't get the diesel started. I had started at home but since I did not have a water source I only ran it for about 15secs. I did the same as I was being back down the ramp. The only difference from last year is that I changed the 2nd filter. .

I Went to start it again and it would not catch. Used some starting fluid and got it to fire but not stay running. Tried to bleed the second filter, and the injector but no luck.
I pulled the boat. THis is what I know for sure
1)I can get a small steady stream of fuel from the line going from the fuel tank to the primary filter.

2)If I remove the line from the manual primer and lay it under the engine I can get a steady stream on fuel from the primary filter to the end of the primer hose

3) I can't get any fuel to the primer. When you pump it and open a bleeder I can hear a sound. I'm thinking the diagram is wore out and not strong enough to pull the fuel to the primer.

Any thoughts?? with the decompression switches off, when the engine is turned over does it use the same pump to pull fuel?

John
Hoping for a change in my boating Karma

I googled it and there are alot of discussions on this same topic. Example
http://www.cruisersforum.com/forums/f54/fuel-injection-problem-yanmar-2qm15-2080.html
http://boatdiesel.com/BDR/Forums/Thread.cfm?CFApp=4&Thread_ID=306

[This message has been edited by mango madness (edited 08-03-2008).]

Sure sounds like you got air in the fuel system. Look at this old web page and scroll down to the part labeled bleeding the fuel system. http://www.j30.org/html/technical/articles/diesels.html

On your primary filter, do you have a hand pump to prime? I've got a Racor and it has a pump on the top of the housing that makes priming easier. I also open the compression relief levers and have someone run the starter while I bleed the system to get out the air.

The fuel lift pump is the pump on the aft stbd side and as you indicate has a diaphram. If the diaphram is shot, you'll either get diesel fuel leaking to the crank case, or diesel fuel leaking out the side.

[This message has been edited by Rhapsody #348 (edited 08-04-2008).]

Forgot to answer this one - the fuel lift pump is the one that feeds the 2 micron filter on top of the engine, then to the High Pressure fuel pump that drives the injector nozzles. The fuel lift pump is driven by a cam lobe as the engine turns, so if you open the compression reliefs and crank the engine, it should help prime the system. I find the handle on the side of the lift pump minimally effective when priming the system.

The HP fuel pump is also driven off cam lobes - don't screw with the insides of this pump as it needs a special test bench to get the internal timing right. Just make sure that you use fresh copper washers on the fuel line banjo fittings or you may have an air leak.

I am not sure I completely understand your problem, but let me pass on something I learned about 4 months back when fooling around with my high pressure pump on another project. I removed it, emptied the fuel from it, and then reinstalled it. I then couldn't get fuel to come out of the output holes when I turned over the engine in the priming process. In some kind 2qm15 net forum somewhere, I read that you have to fill the high pressure pump with fuel which may entail physically pouring fuel into the unit to get all the air out. I did this and it did the trick. I then went on to bleed the injectors and got the engine to start again. In my normal bleeding after changing out the primary fuel filter, I normally don't have to go any further than the input pipe to the high pressure pump by using the pump handle on the low pressure fuel pump to clear air out of the input pipe. Since the HP pump is lower than the fuel filter unit, fuel stays in the HP pump and no air gets to the injectors. Hope this helps.

Thanks for the help, I went to the sites that Mango found. One of the suggestion was to put a manual squeeze pump between the primary filter and the lift pump. My manual pump on the lift pump doesn't seem strong enough to get the fuel to it. Putting a squeeze bilb in will a least get the fuel there to start the bleeding process. I have a 2 micron filter in the primary and there seems to be some schools of thought that suggest it should be a 10 micron filter.
I'm not sure how I loss the feed to the lift pump, but I need to get teh fuel back there to start the bleeding.
JOhn

It's definitely air in the system. I've seen the squeeze bulb tip you mention and it can work. Another solution is the Racor filter housing with the built in hand pump. I've got one like the picture below shown when I removed the Yanmar for rebuild. It has plenty of capacity to prime the fuel system via the hand pump (white handle on top of filter housing).




[This message has been edited by Rhapsody #348 (edited 08-04-2008).]

Do you remember where you purchased the filter? I havn't come across that style. What filter are you using 2 or 10micron?
thanks for the help
John

[QUOTE]Originally posted by Rhapsody #348:
It's definitely air in the system. I've seen the squeeze bulb tip you mention and it can work. Another solution is the Racor filter housing with the built in hand pump. I've got one like the picture below shown when I removed the Yanmar for rebuild. It has plenty of capacity to prime the fuel system via the hand pump (white handle on top of filter housing).


[This message has been edited by whk (edited 08-05-2008).]

I talked with the folks at Torreson marine, they told me that the lift pump has probably failed. You can't buy the diaphram any more you have to buy a new pump $75.00. So I'm going to try that, but I will also plan on bring a squeeze bulb with me, just in case the new pump can't bring the fuel up. I'm also replacing the 2 micron primary with a 10. If the new pump works, next year I will replace the Racor filter with one that has a manual primer in case this occurs again.
Phantom364

I'm using 10 micron now, but used to use 2 micron. The housing I have is no longer made, but there is an equivalent - look at this on eBay: http://cgi.ebay.com/ebaymotors/Raco...itemZ290222611648QQrdZ1QQsspagenameZWD1V

You can get 2, 10 & 30 micron spin on elements for this.