Filter changeover and bleeding issues

[Capn Pete]

After launching my Oday 322 and heading for our summer marina, the engine ran fine for about an hour and a half, then performance began to suffer before the engine crapped out completely. Attempts to restart met with varying degrees of success until, finally, nothing. TowBoat US took me to the nearest YC for an overnight mooring.

Yesterday I replaced the primary and secondary fuel filters and started to work through the bleeding process. But I couldn't get fuel (w/ or w/o air bubbles) to come out the bleed screw on top of the secondary filter, despite endless pumping of the priming lever on the lift pump. Took the fuel intake hose off the lift pump and tried sucking fuel out of the line, but no luck. (FYI, there's about 6-8 feet or so of fuel line between the primary and the lift pump.) I finally threw in the towel for the day and went home to ponder things (including the possibility of calling TowBoat US to haul me the rest of the way to my summer marina).

When I got home, a new possibility occurred to me: After changing the primary filter, should I have filled the filter chamber completely with fresh diesel? There was fuel to just over the top of the filter element, but still room in the chamber for more.

My thinking was that, if you had a cup of soda with a cap on it (the filter chamber), and a straw poking through the top (the fuel take-up line), but the straw didn't reach the level of the soda, you could suck until your cheeks imploded and still not be likely to draw any liquid through it.

Analogy sound? A possible solution to the problem? Should filter chambers be filled up after a filter changeover? Anything else I should try?

Thanks in advance for the help.

Pete
s/v EmmieLou (O-322)
Little Silver, NJ

 

[alexco38]

I have a squeeze bulb before the filter to fill the bowl and line with fuel.

 

[abaragones]

Hi Pete, having had an issue with air in my diesel fuel lines I just went through this over and over and over.

I few things, what primary filter do you have in your boat? When you suck the line at the lift pump, did you get any resistance? No insult here but are you sure the tank valve is open?

If you are sucking from that hose and no fuel is coming (and your tank is full), it has to be air coming in, maybe your primary filter cap/actual filter element/bowl (all this depending on your primary filter) is not seating well, Orings are distorted? Understand your analogy but if you have a good seal all over your fuel system you should be able to fill the filter up and then get fuel through the hose.

Ps. Many of the racor filters do recommend to fill the element/filter bowl full with diesel when changing filters.

Abe

Ps. Wish I could join you this July, work is on the way, next year will be!

 

[Bill Roosa]

Well it worked fine (presumably) until you did what exactly?
sounds like air in the fuel system. This is pretty straight forward stuff. work the air out starting at the fuel tank and proceeding in line to finish up at the injector pump.
You soda can analogy does not hold water (or diesel) as there is another "straw" that allow more "soda" into the can. As you suck out the air the other straw which has it's other end submerged in a large source of soda feels the vacuum and soda flows to the can.
Removing all the air you can is not a bad idea as that is that much less you have to bleed further down the line. I'm pretty sure there is a bleed screw on the top of most filters for this purpose BTW
Since you can't get fuel out of the pump inlet I'm thinking the fuel line is somehow blocked or restricted or you are using your mouth (max vacuum is <<<<<1psi) and can't suck through the filter (most of us cant suck through a filter BTW so don't feel like a wimp)
I'd go to the primary filter inlet and see if fuel is flowing. re-bleed the primary filter, then see if fuel is flowing out of it........secondary filter same same ...... injector ......
you get the idea. Become highly methodical in making sure fuel is flowing and air is not present then move on to the next item in the fuel line

 

[Capn Pete]

Well it worked fine (presumably) until you did what exactly?
sounds like air in the fuel system. This is pretty straight forward stuff. work the air out starting at the fuel tank and proceeding in line to finish up at the injector pump.
You soda can analogy does not hold water (or diesel) as there is another "straw" that allow more "soda" into the can. As you suck out the air the other straw which has it's other end submerged in a large source of soda feels the vacuum and soda flows to the can.
Removing all the air you can is not a bad idea as that is that much less you have to bleed further down the line. I'm pretty sure there is a bleed screw on the top of most filters for this purpose BTW
Since you can't get fuel out of the pump inlet I'm thinking the fuel line is somehow blocked or restricted or you are using your mouth (max vacuum is <<<<<1psi) and can't suck through the filter (most of us cant suck through a filter BTW so don't feel like a wimp)
I'd go to the primary filter inlet and see if fuel is flowing. re-bleed the primary filter, then see if fuel is flowing out of it........secondary filter same same ...... injector ......
you get the idea. Become highly methodical in making sure fuel is flowing and air is not present then move on to the next item in the fuel line

I didn't do anything unusual or different before performance began to suffer and die.

FWIW, the primary is an older Groco Model GF-375 (cast bronze, no water separator bowl). Also, both filters were pretty skunky looking compared to their replacements (or compared to anything normal, for that matter).

I'll go back to square one and open the primary, fill the chamber and reseat the cap (making sure the O-ring is properly seated). I'll check the infeed/outfeed to the filter chamber, too. My recollection is that they're both at about the same level, near the top of the chamber, but that recollection could be off. (Seems strange, I'll admit, that the outfeed from the filter to the lift pump wouldn't be lower, to prevent against a possible airlock.)

I was trying to be methodical, figuring there was no point in bleeding the high-pressure pump or injectors until I had the secondary filter bled. Guess I have to go back and be even more methodical. It might also help if I had a helper, so I didn't have to keep running up and down the companionway steps to do it all myself, but I don't know if that's doable.

Updates to follow as circumstance permits.

Pete
s/v EmmieLou (O-322)
Little Silver, NJ

 

[Capn Pete]

One other thought: Is there a filter or strainer built into the lift pump? If so, is it easily accessible? Can it be cleaned in fresh diesel, or would it have to be replaced?

 

[weinie]

Are you sure the lift pump didn't crap out on you?
and as above check the lift pump filter if it has one:
http://www.pbase.com/mainecruising/facet_fuel_pump_filter

 

[fireman416]

I had the same issue last year. I ran my filters dry and the engine stalled. I worked the system from back to front and finaly found that the pet cock on top of the fuel tank had been closed by accident while departing the marina. Sucked diesel back in the lines and refiled filters and was on my way........stunk like hell for a while till I could shower up

 

[abaragones]

Pete, if you have the 2GM20F, the lift pump doesn't have a strainer.

Our 322 came with the net at the bottom of the pick up tube, inside the tank, if your filters were blackish and you can't get fuel then you might want to take it out (took mine out last year), it can be completely restricted!

Good luck

 

[Don Crowther]

"Took the fuel intake hose off the lift pump and tried sucking fuel out of the line, but no luck"
I don't know your fuel system was this line between the fuel tank and lift pump or lift pump and filter. Check your lift pump for output and your pick-up tube in tank. I guess what i'm saying is start at the beginning and work your way forward.
I hope you find your problem soon.

 

[Warren Milberg]

The primary fuel filter housing on my 2GM20F has an "O" ring on the underside of the upper housing into which the lower cartridge holder is screwed. It can sometimes be a challenge to seat this "O" ring perfectly when replacing filters (and I fill up the unit with clean fuel whenever replacing the filter cartridge). If not seated perfectly, it lets air into the system and the engine quits. Do you have a similar filter setup?
Also, it can help to rotate the engine by hand to move the cam lobe allowing the lift pump handle to move through a complete stroke. If the the pump is stuck on the lobe you can pump all day and never get fuel into and through the system.

 

[ChuckCC]

Sounds like the same thing that happened to me in my '86 Cal33. It turned out to be a very dirty fuel tank. I took out the tank and had it cleaned out by the local mechanic and I replaced the fuel lines just to be sure. I also added the bulb in the fuel line to help with bleeding the line, works great.

I may be way off base but the mechanic says this is fairly common.
Best of Luck
Chuck

 

[Dave602]

I never had any luck with the lift pump on my 2GM20F. I installed a bulb like may others, it works great. Go through and make sure all your connectors are tight. I had bled and bled once and had a slight leak on one of the hoses. Also consider if you fill your filters prior to bleeding you are inserting unfiltered fuel in the system. The bulb or a pump will push fuel to the HP pump through all the filters.

 

[lehighsail]

FWIW: I changed my secondary filter at the beginning of this season and could not get it to bleed thru the top of the filter screw by pumping the fuel lift pump on my 2gm20. After pumping for an hour I gave up. The next day I tried again and realized that I wias not pumping the arm completely...in other words when you lift it up, keep pressing it up after you feel resistance and it worked!! When you're dumb, you gotta be tough.