6V92 stalled - need advice asap

[captddis]

First did you CHANGE the sec filter? March does not mean much. Run a hose from the secondary filter of the running engine to the other secondary, run the running engine and it will prime the dead engine. Then while one engine is running start the non running engine. Both should run. If the bad engine is out I would suspect a broken blower drive. The fuel lines and tubing is 5/8. i have never seen one of those lines plug up.

 

[Genesis]

I have (seen the fuel lines plug up) - MINE did, forcing me to come in on one engine.

My recommendation on the vacuum tank is from personal experience

The secondary has to be VERY plugged for the engine to not to run at idle. When the secondary gets loaded it will start to misfire at higher power levels as there is insufficient fuel pressure in the rail with the consumed fuel; this limits output but won't shut the engine down.

 

[doc g]

Dave, great idea!!!! I like that one ,good to know if you ever have a fuel pump die. I think I'll make up a line with the fittings just to have it onboard........Pat

 

[captddis]

I have (seen the fuel lines plug up) - MINE did, forcing me to come in on one engine.

My recommendation on the vacuum tank is from personal experience

The secondary has to be VERY plugged for the engine to not to run at idle. When the secondary gets loaded it will start to misfire at higher power levels as there is insufficient fuel pressure in the rail with the consumed fuel; this limits output but won't shut the engine down.

Well I HAVE seen engines not run because of the secondary. Do you have to dispute everything??

 

[mobilemn1]

Bob, just wanted to check to see if everything was still running ok,,,and did you find the filters that you needed.

It was nice to meet you guys, hope you have a nice pleasant trip the rest of the way home.

 

[Pascal]

if your genny has an electric lift pump, disconnect it's output and run that to the DD secondary inlet. turn on the genny lift pump to prime and then crank...

sound crazy, but i did that once to get home...

that will eliminate any doubt about the engine (except the fuel pump...)

or if you want to use that to prime the system, connect the line to the primary inlet...

 

[mobilemn1]

Bob,

Maybe on your next stop along the way, see if you can find some FFPF, it
is in a small white bottle with a red and green label. If it was a water problem that you had today, that will bond the water with the fuel to help burn it on out. Add about 3 bottles to each tank, what the filters don't catch you should be able to burn. If it was trash, then you should have enough filters with what you picked up this evening to see your way home.

Happy boating

 

[34Hatt]

Bob,

Maybe on your next stop along the way, see if you can find some FFPF, it
is in a small white bottle with a red and green label. If it was a water problem that you had today, that will bond the water with the fuel to help burn it on out. Add about 3 bottles to each tank, what the filters don't catch you should be able to burn. If it was trash, then you should have enough filters with what you picked up this evening to see your way home.

Happy boating

Oh Boy now you did it hold on to your Shorts!!

 

[bobk]

I tried to get this off earlier but was out of Verizon range.

So here is the scoop. We are underway this morning and have made about thirty five miles. The engine seems OK.

First, many thanks to everyone who helped and a special thanks to Darryl Hollis (mobilemn1) who drove about 45 minutes to help in person. This forum has a great bunch of people.

Darryl brought a fresh set of eyes and we did a few more diagnostic things then decided WTF, lets change the Racor. I primed the system with fresh fuel from a jug, it started and ran at the dock, but was erratic and almost stalling at idle. We had to drive into Washington about 30-35 miles away to get some secondary filters and after changing the secondary (again primed from a jug) the engine started on the second try and kept going after it pulled the air out.

Boy am I red-faced. When it first quit my inclination was to change filters but then I got hung up on the apparent blockage at the priming pump. That led me on a wild goose chase that should not have happened. I’ll pull the pump and either service it or replace it when I get back to a marina again. Lessons learned, … try the easy stuff first, and allow for coincidence. I’ll also make up a long fuel hose that will let me prime either engine with either pump.

Bob
Chateau de Mer
1981 Series I MY

 

[Genesis]

How long had it been since the secondary had been changed?

Its certainly possible for a plugged filter to do this but the secondary has to be REALLY plugged (since its under ~60psi) to refuse to run at idle where actual fuel demand is pretty low. I've seen this happen a fair bit of the time with RACORs (primaries) as once you start to pull significant vacuum dissolved AIR is pulled out of the fuel and that disrupts the clean flow of fuel to the engine pretty quickly. Someone else noted that they've seen a plugged secondary stop the engine at idle; that makes two!

My "general rule" is that filters get changed with the oil, both primary and secondary, and I monitor the primaries with a vacuum gauge. That should keep 'ya out of trouble.

You can put a pressure gauge on the secondary ("Tee" it off the hobbs switch) which would provide an instant check for this sort of condition but this has some hazard associated with it related to leaks (about the same as an oil pressure gauge) since it is under significant pressure (~60psi.)

BTW you might be interested in this article I wrote for BoatDiesel about retrofitting a more modern filter system combined with a priming/polishing pump. Its not terribly expensive and will keep that secondary as a true "last chance" filter as this setup will filter to or beyond where the secondary does. That setup is VASTLY superior to the RACOR setup usually used in terms of fuel quality and the best feature of all is that it goes a LOT further between filter element changes as well.

http://www.denninger.net/filters/out-with-the-old.htm

 

[mobilemn1]

Bob, as YB says, that's what it's all about. Hoffers helping fellow hoffers, just pass it on.

Safe journey

 

[bobk]

I change primaties and secondaries each time I change oil. Everything was fresh in late March. Wierd how so much got past the Racor. I'm running on a 20 micron Racor now as that is what was on board. Since I cruise slow, it ought to work. So far so good.

Again thanks everyone.

Bob
Chateau de Mer
1981 Series I 48 MY

 

[Genesis]

Wow. That is... disturbing.

The "last chance" filter is a nominal 7 micron (if you're using the "stock" element.)

For that to plug on less than 100 hour intervals unless you've had to change SEVERAL RACORs is more than a bit unusual.

Check and make sure your RACOR isn't being bypassed somehow (e.g. element that doesn't seal on the tube, etc)

 

[34Hatt]

First did you CHANGE the sec filter? March does not mean much.

Well Guess Ill say it GOOD CALL DAVE!!

 

[mobilemn1]

to give a little more history of the problem, the main filter was the one completely or near totally stopped up. Once Bob and I changed that one the engine fired. But Bob knows his boat and the boat would not idle as stable as it had before. We were trying to eliminated one thing at a time before condemning the pump on the blower as the culprit. The engine would idle at between 500 and 650 rpms, and Bob said it had always been stable at 600 on the nose. But what we did eliminated the main fuel pump, and he picked up some new secondary filters and all was ok with the idleing, back to 600rpm.

Bob had refueled the day earlier and I suspect that if the fuel had been delivered fresh to a provider that he thought was safe, there were some floating biologicals in the fuel that caused the problem. Most people never ask when someone had fuel delivered before pumping and fuel even from a reliable source can be affected by a new fuel supply. It takes a while for the gunk to settle back down below the supply pick up.

 

[jim rosenthal]

Glad you are back on the "road". And very nice that a HOF member helped you out, that's "right neighborly", as they say down there.

I had Racor filters in the past with Cat engines. I had a number of problems with jammed injectors, etc. I went to much larger Racors but then changed those out for Fleetguard systems I got from Tony Athens. They are rated for a common-rail engine the size of a Cummins M11- about 650 hp. Quite a bit larger than my 370Bs. They seem to work very well indeed.

There is another advantage to using spin-on type filters like these: when you can't get Fleetguard spin-ons, you can cross the ID number over and get NAPAs (which are made by Wix, and very good) or Baldwins (also good), etc. You are not limited to Racor products. There are two separate cans- one is the fuel-water separator unit and the other is the primary fuel filter. And then there is a secondary or "last chance" filter on the engine itself..also a Fleetguard filter.

There is also a good discussion of fuel filtration on Tony's web site at www.sbmar.com, I think it is. Talks a lot about how fuel filters are tested and rated; easily readable and very helpful. The latest version of this system that he sells also incorporates a fuel priming bulb which is a simple and effective way of refilling the system when you've changed the filter cans.

 

[Genesis]

Yep - that write-up I linked to is Tony's system.

HIGHLY recommended.

I was NOT a believer until I lived with it for a while.

I became one.

Fast.

 

[MikeP]

Ditto to the above - the Athens system is excellent - excellent performance, easier to service, takes less space...what's not to like? I replaced my Racors several years ago.

 

[SKYCHENEY]

If you run a 2 micron Racor, then the secondary is just a fail safe to catch something that the fuel pump spits out. You should never actually have to change that secondary as the the Racor should do the job, just monitor the vac gauge.

 

[captddis]

If you run a 2 micron Racor, then the secondary is just a fail safe to catch something that the fuel pump spits out. You should never actually have to change that secondary as the the Racor should do the job, just monitor the vac gauge.

Thats right. I will never understand the logic of using a 30 mic primary filter. Have to laugh at hearing that it maximizes filter life. Using a 30 mic primary will cause the secondary to plug BEFORE the Racor. Not to mention letting all the crap run through the lines and pump. I want the racor to stop the crud not the secondary.

As far as the Fleetguard filters, I keep hearing that they last longer. How? Where does the contaminates go? If they plug the racor but not the fleetguard where are the particles going? Magic?