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Old 12-08-2015, 06:57 AM   #61
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For trouble shooting , use the bulb and an out boartd tank filled with diesel to pressurize from a tank fitting.

Any problem will show as a fuel leak, EZ to find with paper towel strips at every fitting.

For remote cruising I would install an electric fuel pump, for bleeding , and should the factory lift pump die.
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Old 12-08-2015, 07:28 AM   #62
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Switch the fuel supply lines and see if the problem follows the fuel supply. This will tell if the problem is fuel delivery or engine system fuel pump or injection pump
I think that's my next move, if for no other reason than it's easier to do than to put the new lift pump in (much better physical access to the tank top than to the back side of the engine).

RTF, yes, exactly the same components in the same sequence. Eventually, I may end up replacing all of them - but I'm still hopeful it's not the injector pump.

Too bad all these lines aren't made of clear tubing - that should make bubble spotting a whole lot easier.
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Old 12-12-2015, 07:37 PM   #63
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UPDATE: Fixed - maybe!

I swapped the fuel line to draw from the other engine's pickup - bled for a while (OK, a long while), and got it started. Let it run at least 20 minutes w/o issue. Then let it sit for two days - since sitting has always revealed the problem. Started and ran - a little rough in the first 20 seconds or so, then ran fine. Let it run at least 10 minutes w/o issue. Then let it sit for two more days - and today, it started, was a little rough in the first 20 seconds - and then ran like a champ.

Is it fixed? Maybe. Hopefully. I say that because I have now pulled the "suspect" pickup tube up out of the tank as far as I can (can't remove it completely because the engine room ceiling is too low), and I didn't see a single thing wrong with it. It's solid steel welded to the bottom of a steel pipe elbow, and the welds look solid, and the pipe does, too.

After today's successful start, I added a "T" to the fuel line to the genset, and hooked the good engine to it, and made sure they'll both run from the same supply, which they do. That's how I'm going to leave it for a while. Until the problem occurs again (and then the new lift pump goes in), or until after the impending trip down to the Keys (when I think I'll put the new lift pump in, just because I know the old one is pretty old).

So what's the lesson? Perseverance, I guess. And that sometimes, even if you get something fixed, you don't really know what was wrong - and I can live with that.
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Old 12-12-2015, 07:52 PM   #64
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check that both the main engine and generator will both run full load at the same time, not just at low load(low fuel burn and flow)

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Old 12-12-2015, 09:52 PM   #65
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check that both the main engine and generator will both run full load at the same time, not just at low load(low fuel burn and flow)

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Well, we never run the generator while we're running the boat - but I did run them at the same time, and loaded up the generator - no problems. I think all three of my engines could run all-out at the same time, on these pick-ups - they're very large.
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Old 12-13-2015, 12:03 AM   #66
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Brian.
From personal experience I always put a non return ball valve in the fuel feed line where it exits the tanks, works for me.;
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Old 12-13-2015, 06:58 AM   #67
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"Too bad all these lines aren't made of clear tubing - that should make bubble spotting a whole lot easier."

No problem, OTS, purchase an armored sight glass from the local refrigeration supply.

These are robust and work quite well. Under $20.00

The units like a cigar can be has with a male fitting on one end a female on the other .

Many models have no moisture indication inside.

Here is a look at dozens,

https://www.johnstonesupply.com/stor...028313-p1.html
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Old 12-13-2015, 07:41 AM   #68
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From personal experience I always put a non return ball valve in the fuel feed line where it exits the tanks, works for me.;
Some PO did that - and it sure made putting in the "T" easy!
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Old 12-13-2015, 07:50 AM   #69
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"Too bad all these lines aren't made of clear tubing - that should make bubble spotting a whole lot easier."

No problem, OTS, purchase an armored sight glass from the local refrigeration supply. These are robust and work quite well. Under $20.00

The units like a cigar can be has with a male fitting on one end a female on the other. Many models have no moisture indication inside.
They're for refrigeration systems, so they're designed to have compressed gas flowing through them - but you're saying a fluid is OK? And - dumb question - although they're called a "sight glass", they seem to have some kind of gauge or indicator in them. Would you able to see the actual fuel, so you could differentiate between the liquid (red) and an air bubble (clear)?
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Old 12-13-2015, 08:09 AM   #70
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Be careful with "T" fittings in fuel lines. Air leaks in the non-working side of the system can be exploited by the working side. In other words: My main engine was able to suck air into the genset's fuel system and make it impossible to start after long days cruising the ICW. The generator ans each engine should (in an ideal world) have their own fuel feed from a tank or manifold.
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Old 12-13-2015, 08:32 AM   #71
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Be careful with "T" fittings in fuel lines. Air leaks in the non-working side of the system can be exploited by the working side. In other words: My main engine was able to suck air into the genset's fuel system and make it impossible to start after long days cruising the ICW. The generator ans each engine should (in an ideal world) have their own fuel feed from a tank or manifold.
I understand what you're saying, but in my case, the T is right out of the tank top, and then both lines dip down almost immediately, to about 6" below the level of the T. With no fuel moving through the non-working side (the genset line during a day of cruising with the genset not running, as per your example), it doesn't seem possible for air introduced at the T or in the working side (the main engine, running all day long) to create more than a very small air bubble in the non-working line. And it would be trapped in its Racor when the non-working line became the working line.

Yes? No?
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Old 12-13-2015, 08:43 AM   #72
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It's not so much where the "T" is because it doesn't pull it from there. Well, not always. Any leak, not matter how small, that can pull air in ANYWHERE along the entire path of the fuel line to the genset will have negative pressure on it. What happened to us was a small leak over 6' away at the fuel inlet to the generator. It could also put negative pressure on the injector pump... but TBH I don't know if that is even "a thing" or not... Ski might be better qualified to answer that than I. Still, a system designed to have fuel pressre going one way, may cause problems if there is pressre sucking it the other way (including the whole introduction of air we discussed earlier). :-)
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Old 12-15-2015, 07:42 AM   #73
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"They're for refrigeration systems, so they're designed to have compressed gas flowing through them - but you're saying a fluid is OK"

When use in refrigeration systems the freon IS a liquid and the purpose of the site gauge is to see bubbles , to figure out if the system is fully charged.

Freon is colorless and the bubbles are EZ to see.

Same ease for diesel fuel, died or undied.
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Old 12-15-2015, 08:11 AM   #74
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"They're for refrigeration systems, so they're designed to have compressed gas flowing through them - but you're saying a fluid is OK"

When use in refrigeration systems the freon IS a liquid and the purpose of the site gauge is to see bubbles , to figure out if the system is fully charged.

Freon is colorless and the bubbles are EZ to see.

Same ease for diesel fuel, died or undied.
OK, makes sense. After this experience, I love the idea of having a way to spot air in the system. I'll look into this further - thanks!

BTW, I've started the boat a few more times - with one day between starts - and it seems like we're back to normal performance now. So, although I never found a smoking gun, all the clues point to some kind of problem with the starboard engine's tank pickup. After this upcoming trip is behind us, I'll probably go back and start switching lines around, to see if the problem moves to whatever engine is connected to that one pickup.
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Old 12-16-2015, 07:48 AM   #75
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"all the clues point to some kind of problem with the starboard engine's tank pickup."

Most boatyards have fuel delivered by the same folks that supply gas stations and truck stops.

A bit of bio diesel is a great solvent and may have knocked enough gunk loose to clog the tank feed screen.

Had it happen on a '80 diesel rabbit when switching from home fuel oil to "real" road diesel. Big PIA!
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Old 12-18-2015, 05:46 PM   #76
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I didn't read all the responses, but the fuel pick up tubes can crack and split. So when you have a full tank it works fine, then as the fuel level drops (below the split) it sucks air causing the air in the system.

They sell fuel dip tubes with plastic tubes so you can flex the tube into the tank enough to get the tube in, then screw it in tight.
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Old 12-19-2015, 12:27 PM   #77
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I didn't read all the responses, but the fuel pick up tubes can crack and split. So when you have a full tank it works fine, then as the fuel level drops (below the split) it sucks air causing the air in the system.

They sell fuel dip tubes with plastic tubes so you can flex the tube into the tank enough to get the tube in, then screw it in tight.
I tried to remove the existing tube for a full inspection, but it's too long to be removed, given the relatively low engine room ceiling height. (The engine room is below the salon sole, so there's only about 20" of clearance.) When this upcoming trip is complete, I may take a pipe cutter to the existing tube to remove it, knowing full well I'll have to replace it with something like the plastic tube of which you speak.
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