RPM's Dropping

[Steph]

On my Cal 28 with Westerbeck 13, my RPM's intermittantly drop from 2800 to 2200 then come back up. I have to admit I haven't changed the fuel filter in years (bad, I know). I suspect that's the problem.... is it hard to change the filters and bleed the line? Could it be anything else? Thanks, Steph

 

[Bad Obsession]

I have a Racor. Changing the filter is child's play. Simply open the top vent hole on it, bleed the filter through the bottom into a large cup, unscrew the old filter, unscrew the bowl off of the old filter, clean the bowl, put the bowl on the new filter, fill the filter up with diesel (I like to fill it up with injector cleaner), put the new filter on, and then use the pump to bleed the air out of the filter (keep pumping until diesel squirts out the top vent hole). It is VERY easy with a Racor.

What type of fuel filter do you have?

 

[Rob2435]

Similar

I've had a similar issue, usually in a following sea with about a 1/4 tank of fuel. Most likely cause by fuel sloshing around and moving away from the fuel pickup in the tank.

 

[centerline]

the fuel filter must be changed regularly for dependable service from your engine, and the more you do it, the easier it will become.
Im not sure how the fuel filter setup is on your engine, but some systems did not have an anti drain back valve.... that makes it tough. you can install an aftermarket primer pump in the system and then its a breeze to change filters and they are also serve as an anti drain back valve.

if you have a soft line coming from the tank to the filterbase, try clamping it off near the filterbase so the fuel will not drain back to the tank, then fill your new filter with clean fuel and have it ready to install as soon as you remove the old one..... once you have the new one installed remove the clamps from the line. without excessive air in the system it should make priming a lot easier job. before loosening the filter, I would clamp off the return line as well just to make sure as little air as possible enters the system.... MAKE SURE TO REMOVE THE CLAMPS BEFORE TRYING TO START THE ENGINE.

 

[Steph]

thanks... another question

Thanks for the advise.... but does one have to change the secondary filter at the engine as well? Thx.

 

[RichH]

Fuel filter material, a porous 'technical' paper, is typically epoxy encapsulated cellulose fibers and should be changed yearly.
The epoxy encapsulation of the cellulose fibers isnt 'perfect'. If you have water or 'emulsified' water in your oil, and just about everyone has emulsified water in their oil ... the water will start to dissolve or 'soften' the cellulose component in the filter media -typically after about 12 months in contact.

 

[centerline]

the primary filter is a water trap filter. the secondary is a finer, back up filter. your fuel pump and injectors wont tolerate any contamination..... the filter media in the primary is such that fuel will pass thru it easily, but as soon as water contacts it, (depending on how much water) it swells up and shuts itself off so nothing gets thru..... it should be changed frequently. the secondary filter media is a finer micron, but water will usually pass thru it if it gets thru the primary and it should be changed at least once a year, depending on how much you use the engine......
the thing about diesel is, it is hydroscopic. it will attract and hold water in suspension with itself. if your diesel is cloudy, it has absorbed water and should be changed. as long as the water molecules are bound with the diesel molecules, it will pass thru the filter media, but it is hard on the injectors and doesnt burn as clean. it loses some of its ability to combust properly while running and starting and it is prone to grow bacteria called algae... once algae gets started in your system, its difficult to get rid of and it grows.... it will plug filters and fuel lines constantly.... its better to keep clean fuel and clean filters.

 

[RonRelyea]

Brand of Injector Cleaner????

Bad Obsession ... I went to my local Marine / Auto Supply store and asked for Diesel Injector Cleaner and the counter guy looked at me like I had three heads .... can you recommend a name? Is Seafoam an injector cleaner?

Thanks

Ron

I have a Racor. Changing the filter is child's play. Simply open the top vent hole on it, bleed the filter through the bottom into a large cup, unscrew the old filter, unscrew the bowl off of the old filter, clean the bowl, put the bowl on the new filter, fill the filter up with diesel (I like to fill it up with injector cleaner), put the new filter on, and then use the pump to bleed the air out of the filter (keep pumping until diesel squirts out the top vent hole). It is VERY easy with a Racor.

What type of fuel filter do you have?

 

[Stu Jackson]

On my Cal 28 with Westerbeck 13, my RPM's intermittantly drop from 2800 to 2200 then come back up. I have to admit I haven't changed the fuel filter in years (bad, I know). I suspect that's the problem.... is it hard to change the filters and bleed the line? Could it be anything else? Thanks, Steph

Steph, I'd bet that most of us when we bought our boats put off doing the diesel filter change because of "fear of bleeding." Yikes, the engine won't start again and I can't use the boat. OK, OK, at least I'll admit to it! :dance:

It's pretty easy to do. The tricks I've learned are these:

1. Bad Obsession is right, use injector cleaner to refill the bowl. Why? 'Cuz it's easier to dump a load of liquid into the bowl from a plastic container than it is to find clean fuel - you'd have to open the fuel fill and catch it somehow and then close it up. Injector cleaner is injector cleaner. Read the labels in the store. I don't think I've ever bought two of the same little pint bottles in 13 years. They all worked. The reason: it lets less air into the system and shortens bleeding time, especially without an electric fuel pump.

2. Go to the Torreson website, www.marinedieseldirect.com, and download your engine manual or at least the bleeding instructions. It'll tell you exactly how to do it.

3. Don't plan on sailing the weekend you do it, just in case. Oddly enough, if you do it that way, your engine WILL start right up and you CAN go sailing!!!

4. Once you've done it once, you'll kick yourself for finding out how easy it usually is.

5. If you have an electric fuel pump, it's a lot easier to bleed, rather than banging your knuckles on the manual pump on the Racor.

6. ONLY do ONE filter at a time. If something doesn't work, at least you'll know where to look.

7. Be careful with the O rings. Make sure they are seated properly and rub some fuel on them before you put the NEW ones on.

8. Check to see if the inlet screen on the fuel pickup hose inside the tnk has been removed. If not, remove it. Either way, make a note on your fuel tank that it has been removed (for the next guy).

 

[Norm1946]

Stu, why should you remove the inlet screen on the fuel pickup hose & how would you remove it?

 

[RAD]

Bad Obsession ... I went to my local Marine / Auto Supply store and asked for Diesel Injector Cleaner and the counter guy looked at me like I had three heads .... can you recommend a name? Is Seafoam an injector cleaner?

Thanks

Ron

Sea foam is the stuff!.....thats what I refill my filters with

 

[higgs]

Change you filters and bleed the system an I bet the problem will be gone.

 

[alexco38]

Fuel delivery

I got towed back to the slip twice in a week. Pretty scary as I was close to shore when the diesel engine acting up. The engine will slow down and speed up, eventually quit. It can be restarted but own't go into lower RPM or idle.

Traced the entire fuel system and found the following:
(1) Fuel hose at the engine cracked at the bend but can not see it visually.
(2) There is a screen inside the fuel pump which is almost blocked. Didn't know it exists.
(3) The pickup tube inside the fuel tank was just a piece of plastic (ABS) on a barb. It let in air because it wasn't glued on.

Engine is a Volvo Penta 2002 circa 1985.

It's not obvious but should be checked every few years. Lesson learned !

 

[Don S/V ILLusion]

Stu, why should you remove the inlet screen on the fuel pickup hose & how would you remove it?

Guess Stu didn't read your question so...

The reason he said that is simple - 1. the screen will get clogged inevitably and 2. you won't know it until it's too late. So removing it eliminates the problem. If you are wondering why it's there in the first place, that is a good question. It serves no purpose except to protect the primary filter from large chunks which will get caught in the filter anyway with no harm.

How - remove the pick up hose, remove the fitting to which it attaches and lift it out of the tank.