Transmission, Turbo, Tachometer, oh my...

[Russell]

That is amazing information. I had no idea that the engine could still run with the lift pump out. Failure of the lift pump when I am off shore has been one of my greatest fears but if you are correct I can still limp home. Good luck and let us know how this turns out.

[jleonard]

Whether you can run without the lift pump depends on the fuel system. If you have full tanks and some "head" pressure to the engine then no problem. If you are low on fuel and the level is below the pum then maybe not.
Either way you should not "fear" a failure. Lift pumps are cheap and easy to R&R most of the time, esp on a Cummins.
On my old Albin I have a diaphram style lift pump. I wanted to make it easier to prime the fuel system PLUS have a backup for the lift pump so I installed an electric pump in a easily closed off loop.
You can also "get home" by using an outboard engine squeeze ball plumbed in line (don't laugh, it works). The squeeze ball cab be used to prime if necessary, plus supply fuel. I have a friend who did this and got back home to RI from Martha's Vinyard once. He and the owner took turns squeezing the ball and running the boat.

[Seaslug44]

Whether you can run without the lift pump depends on the fuel system. If you have full tanks and some "head" pressure to the engine then no problem. If you are low on fuel and the level is below the pum then maybe not.

This explains why with my tanks just over half full the boat yard thought I ran out of fuel a few weeks ago while they were testing my new turbo and injectors. Then, by adding twenty or thirty gallons to each tank they were able to start the motor right up again. Very interesting...

[Seaslug44]

Whether you can run without the lift pump depends on the fuel system. If you have full tanks and some "head" pressure to the engine then no problem. If you are low on fuel and the level is below the pum then maybe not.

This explains why with my tanks just over half full the boat yard thought my boat ran out of fuel and had to be towed back to the dock a few weeks ago while they were testing my new turbo and injectors. Then, by adding twenty or thirty gallons to each tank they were able to start the motor right up again. Very interesting. Also, the fact that my new vacuum gauge on my Racor shows zero pressure combined with the fact that the engine was able to run on either tank while they were more than half full is a good indication to me that I have excellent fuel flow from the tanks to the injector pump.

[Russell]

My lift pump has a thumb operated button (lever) that can be used to pump fuel into a new spin-on fuel filter and then start the engine without the necessity of bleeding the lines. Would this button work if the lift pump ceases to function or is it dependent on a common diaphragm?

[jleonard]

Would this button work if the lift pump ceases to function or is it dependent on a common diaphragm

If it is diaphragm type pump then both features pretty much fail together in my experience.
I had a diaphragm lift pump failure on my Dodge/Cummins pickup. The pump was less than one year old, hat's whay it was difficult for me to diagnose at first. Funny thing was that it was not the "diaphragm" itself that failed.

Short story long, the truck died out 3 times. First time I had to get towed. It was the dead of winter and I "assumed" fuel gelling. Second time (2 months later) I was able to re-prime (although the lever function seemed weak) and fire up. Third time she died on the expressway doing 65 with the entire bed filled with "first weekend on the boat gear". Had to get towed home

Next morning I put a new lift pump in and by 7:30 am it was up and running
I cut the lift pump apart to diagnose the failure. There are 2 little flaps that serve as "check valves" between the chambers. One had disintigrated out of shape and could no longer cover the orifice. The diaphragm was intact but without the check valve function it was useless. (Carter pumps are no longer made in USA by the way)

Fuel tank is lower than the injection pump and maybe level with the lift pump in a truck

[jruesr]

Hello again Seaslug'

We have the same boat and I think you may me missing what your mechanic was telling you. Not for sure but possibly.

My boat had an additional fuel pump below deck. It was plumbed between the fuel filter and the engine. I have seen the same pump on other albins in the same location. I thought I had a picture of everything on the boat but some how cannot find one right now. This little pump is electric. It makes a pulsing sound when powered on.

If its plugged or othewise failed it may be the root cause of your dificulty. It would restrict flow to your lift pump.

I mounted my vacuum gage at the engine and not at the fuel filter. If you put your vacuum gage on the fuel filter as you say, then your gage would read low even if this pump or its lines were plugged. I could not find any information on this pump. Searched everywhere. I do not know if this pump was designed to allow free flow when turned off or not.

I moved my little pump to a location before the fuel filter. I use it to prime the filter and help bleed the system or transfer fuel. Its old and intermittent in its operation. I plumbed a bypass around it so the engine would not have to suck fuel through it.

I followed your blog on boat diesel.com and Tony suggested that you put a pressure gage after your lift pump to see it the engine was getting fuel (5 to 10 psi). This would have told the story.

I think you may now have the answer. Let us know if the new pump is a boost pump or a lift pump. I run my engine without this pump. If my suspicions are correct, you could just eliminate it. I would like to know why its there in the first place. Perhaps the fact that the fuel level in the tanks is below the level of the engines fuel system when the tanks are nearly empty or just low. This little pump just keeps everything pressurized if it is working. Perhaps one of its valves failed and it is now a constant flow restriction thus explaining why your results are so repeatable.

I like the little pump in the location that I have it plumbed with a bypass. I leave it turned off but could use it if necessary for engine operation.

I like your post about the rubber mat over the engine hatch.

Good luck
John
Passages III
Punta Gorda

My engine is still shaking. I was planning to put the boat on the hard and fabricate panels for the kiel cutouts but will delay until my injectors are rechecked.

[Seaslug44]

We have the same boat and I think you may me missing what your mechanic was telling you. Not for sure but possibly.

My boat had an additional fuel pump below deck. It was plumbed between the fuel filter and the engine. I have seen the same pump on other albins in the same location. I thought I had a picture of everything on the boat but some how cannot find one right now. This little pump is electric. It makes a pulsing sound when powered on.

If its plugged or othewise failed it may be the root cause of your dificulty. It would restrict flow to your lift pump.

Once again your advise and insight is spot-on. I asked some questions and learned you are absolutely correct- it's not my lift pump that is malfunctioning but a THIRD FUEL PUMP "down below" that he senses is the cause of my lack of full power. The replacement pump has been ordered. When it is installed I'll give an update.

Thank you again! Now only if you can solve my dilemma on how to remove my old refrigerator from the forward cabin and get the new one in its place without cutting huge holes in my doorways.

[jruesr]

I am very anxious to see your problem solved and I want to know exactly what pump the mechanic installs. I cannot find data on my third pump and although it is bypassed, and the boat gets full rpm, It is flaky and I am interested in a new one.

I ordered one of your mats for the cockpit (from your post on this site). I selected a cleated backing vs your smooth but hope it will keep the water out and act as a noise attenuator.

I will read about the refrigerator.

My boat is on the hard and I have ordered some fiberglass plate to fabricate the kiel shaft opening cover.

If this does not stop the shaking I will be at the end of my road.

John
Passages III

Edit: Find attached photos of my fuel tank pick up tubes. The black tubes are my original albin tubes. The Inside diameter of the hose fitting, in the original tube piping, is .280 inch. The white tubes in the photo are larger tubes that I bought to go in my new tanks. They are 3/8 id hose fittings. I did not use then because Cummins said I need 1/2 inch fuel lines. I bought half inch piping for the entire fuel system and installed it. I wonder if Albin installed this boost pump because they were just patching a problem and not correcting it. All this can be analysed with vacuum gages and hopefully the Cummins mechanic will get to the bottom of it and not break your bank.

My boat now has half inch fuel lines and it does not need the boost pump that came on my boat.

[Seaslug44]

Thanks John. Extremely interesting. I think you are on to something. Three fuel pumps does seem excessive. The Cummins rep just got the pump shipped to him. I'm hoping it will be installed by Wednesday.

[jleonard]

When I repowered my old Mainship with a Cummins 6BTA I installed full 1/2 inch ID fuel lines to the engine per the Cummins installation manual. Never had a fuel flow problem. Remember that these engines flow 45 gallons per hour at approx 1800 rpm and above. Yes most gets returned but the system must be capable fo flowing this amount.

[jruesr]

One more comment,

You say your vacuum gage reads Zero pressure and that indicates that you have good fuel flow from the tanks.

If you have the correct gage (vacuum gage) in your fuel filter it will not read zero while the engine is running. Even with my half inch fuel lines and a new filter, my gage has a vacuum reading. Not Zero. When I run the engine I always read something and now it is below red line on the raycor gage.

Just to be accurate the reading is PSIG. This means pounds per square inch gage, it reads relative to atmospheric presssure. That should read vacuum not pressure. I believe the scale is in inches of mercury instead of psi.

I do not have the scale with me now but will update next time I run the engine. Boat is on the hard now.

Sorry to be technical but if your gage reads zero it is worthless to you. Is it a pressure gage or vacuum gage and what are the units of measure.

John

[jleonard]

I have 2 vaccum gages and they read zero with new filter elements. (30 micron and 10 micron)
When I had the Mainship with the 6BTA the vacuum gage there also read zero with a new element (30 micron).

[Seaslug44]

Problem solved!

Thank you to everyone, especially John (jruesr). Your knowledge and insights have been extremely accurate.

The verdict- that third mystery fuel pump located in the fuel line between the Racor filter and the motor. Not sure what the exact part number is but I do know that it is a stock Cummins pump because it was delivered directly from the Cummins factory along with the proper gaskets. I sea trialed the boat this weekend with the new pump installed but with my fuel pressure set at a medium setting for the initial sea trial and the boat ran great with lots of power. We are in the middle of installing and calibrating a new tachometer so I won't have the exact performance specs for everyone until later in the week but even without the full fuel pump pressure I was able to easily cruise at 18 - 19kts with a top end over 20kts. The Cummins factory rep said he gained an addional 200-300 rpms today once he felt comfortable increasing the fuel pressure to a normal setting. If he was indeed able to gain another 200-300 rpms for me then my cruise may be around 20kts with a top end of around 23kts as I was hoping for with the new turbo, new injectors, new transmission, new water pump, etc... I will report the specifics soon.

[Seaslug44]

By the way, I forgot to mention that the laser tach did reveal that my old VDO tach refused to calibrate properly with the new alternator. The easy fix was to match my 2010 alternator with a 2010 tachometer and that proved to be a very accurate combination.