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Engine stalling

Peter K

Member II
I am having trouble with my M25XPB on my 1988 E32-200.

Problem 1: engine stalls after 5-10 ministers or so

Problem 2: sometime while under power the engine does not respond (or has a very delayed response) to increased throttle

Would appreciate any tips on how to trouble shoot!

Peter
 

bolbmw

Member III
Definitely has the sounds of a fuel supply issue. You can try bleeding it to see if there is air in the system, and if so, find the root cause of the problem. Fuel filter(s) could be suspect as well.

I replaced a lot of components on my 5416 until I discovered that the primary filter housing was letting air into the system, but hey now I've got a completely new fuel supply system and have had zero issues since. I cannot speak highly enough of the Racor 500 filters. The previous CAV filter that was previously installed was complete junk comparatively.
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
a quick search reveals....

http://www.ericsonyachts.org/infoexchange/showthread.php?3585-Racor-filter-application&referrerid=28

Our fuel fixes are mentioned in replies 10 and 19 in their thread. And I did indeed replace the original electric pump, later. No problems now for years. Of course I replaced the fuel tank as well as all the ancient OEM hoses.

(One of these days, when I get a Round Tuit, it would be nice to install the larger Racor 500 series and reduce the # of places for a vacuum leak to even happen.)

Loren
 

907Juice

Continuously learning
Peter, i had the same problem last summer with my 1gm (along with some other issues). After tinkering for a while, I finally just bit the bullet and changed everything having to do with the fuel system. Removed/cleaned/replaced fuel lines, changed our lift pump, changed both fuel filters, replaced all washers, and bled the system... twice... now she runs like a champ and haven't had any problems.

Anyway, hope this helps. Sometimes we know what needs to be done we just don't want to do it...

juice
 

Christian Williams

E381 - Los Angeles
Senior Moderator
Blogs Author
First thing, change the primary fuel filter. You probably have a Racor 200-series spin-on filter.

You'll also be bleeding air out of the fuel system after that.

Lots of help here for that stuff if you need it.

Many procedural how-tos on the subject.
 

Peter K

Member II
Thanks for all the comments. I routed the fuel line so it bypasses the primary fuel filter (Racor 200) and goes directly from the fuel tank to the pump and into the engine. Result is engine runs great with no stalling and no delay in throttle power.

Now or I need to buy a new racor so I don't feed too much unfiltered fuel to the engine. Sounds like need to get the racor 500.
 

Merrimist

Hammy, 'Merrimist' E38 in sunny Bda
Just this weekend past, I experienced a similar problem that you described on my M40 32hp Universal.

Fault finding was immediately centered on the fuel system. After checking draining the water sep bowl on the Racor R24S fuel filter I noted that the fuel lift pump was not operating.
I replaced the fuel lift pump and although engine would start and run, the same issue as previous ensued.
I then found that the 12VDC elec spade fitting (supply to lift pump) was intermittent. After this was made good - stripped and new terminal ends, fuel lift pump operates and air was then heard being sucked in (engine not running) and after close inspection, air (bubbles) were being drawn into the Racor water sep bowl through the drain that had been used to drain the bowl earlier. Bugger!

So it appears that my original issue was bad 12V supply to fuel lift pump. Nothing wrong with the fitted pump - now have a spare :) .
But in the course of draining the Racor fuel bowl, it did not seal shut properly, no fuel leaking out, but allowing air to be sucked in when fuel pump operating correctly.
So although the engine would run, it was a little unsteady at idle. Which brings me back to a couple of the earlier posts - Christian/Juice/Loren about replacing items in the fuel system.

If you have a fuel lift pump fitted, ensure that it is operating correctly. Ensure that all hoses and filters etc. are tight and no air being drawn into the fuel supply.
Good luck and get that filter sooner rather than later.

Good practice is to change fuel filters annually for reliability, more regularly if fuel is dirty or not used for a few years. And good idea to always keep a spare primary and secondary - if fitted, fuel filter onboard. A manufacturer's note that came with the fuel lift pump I purchased reads, ensure 75 micron in line filter be fitted on suction side of fuel lift pump.

Hammy in sunny Bermuda
Merrimist 38-200
 

Frank Langer

1984 Ericson 30+, Nanaimo, BC
When I had a similar problem with our 5416 16 hp diesel a year ago, and couldn't find the cause, a mechanic spent two hours checking everything and couldn't resolve it. Then I read in Nigel Calder's diesel engine repair book about a trick to check for air in the system. He recommended routing a temporary fuel line from the tank to the fuel pump and then dipping the end of the fuel line in a pail of diesel fuel to check for air bubbles while the fuel pump is running but the engine is not. When I did that, I noticed pin-head size air bubbles in the pail where before that the mechanic had sworn there was no air. When I replaced that fuel pump and reattached the filters and lines, all ran perfectly and has been good since.

It's amazing how some tiny air bubbles will cause the engine to run erratically and eventually stall out, but this test helps with the problem solving. If I hadn't found air bubbles when the fuel line was attached to just the pump, I would have added the primary filter next, then the secondary filter until I discovered where the air was entering the system.

Frank
 

Christian Williams

E381 - Los Angeles
Senior Moderator
Blogs Author
Peter,

You're now relying on the secondary fuel filter on the engine. It is small and probably 2 microns. That's all right for the moment, but let's get the primary up and running again.

My opinion is that a Racor 200 is fine for the M25. It's a bit smaller than a 500-series where space is cramped.

If it is original, 30 years or so is asking a lot. The aluminum body may be beat up, threads worn, and so on. I had one with an invisible crack that let air in.

Since the assembly needs to be air tight, a new one is a couple of hundred bucks well spent.

Opinion varies as to the micron rating of the primary filter. Most use 10 micron for that, and 2 micron for the engine filter.

There is an argument to be made for a 30 micron primary, if planning to slog through seas or go offshore. Clogs slower. Won't cause damage because there's still a 2-micron last line of defense on the engine.

I carried five replacements when I used a spin-on. Should conditions stir up gunk in the fuel tank, repeated clogs might occur.

If you have room for a 500-series, they're better and easier and the filters are cheaper.
 

supersailor

Contributing Partner
It has been mentioned before, but my problem that was similar to yours troubleshot out to being a faulty Racor filter that had developed a crack in the aluminum housing and was letting air bubbles into the system. It was located by removing items from the system one by one and running the engine on a hose stuck into a bucket of diesel. I know from the earlier thread that I wasn't the only one that has had this problem. If you have an older Racor, look at it as suspect. If it has this problem, it will likely act differently when hot or cold. It doesn't take much to screw up the fuel system. :confused:

Good luck.
 

bolbmw

Member III
My only rationale for getting the 500 series was the filter design. After analyzing the any of the screw in filter types, and after having spent way too much time than I'd care to admit bleeding air out of diesels, the 500 has clear advantages. With any spin on design you have to prime the system and get air out of the filter assembles. With the 200 series with a prime pump this is tedious and time consuming at best, and with other designs without priming pumps, an exercise in futility unless you have gravity at your favor and can 'burp' the filter or the filter is under pressure.

Not so with the 500, as long as you have the fuel level above the inlet/outlet which are ~3/4 up the filter assembly. As long as vacuum is maintained, the 500 will not let in any air. Drop a filter in, top the assembly up with clean fuel above the mark and screw the lid on. No screwing around with priming, burping or nervous passengers as a lee shore approaches.

That said, they're expensive, large and totally overkill for our small diesels.
 

Tom Metzger

Sustaining Partner
Having a 30 year old 200 series Racor I discovered this year that the rubber gaskets reach end of life after 29 years. I made a gasket for the drain before discovering the vent o-ring had also failed.

The smart move would have been to just replace the whole filter, but I had bought the drain plug before the other problem showed up. The filter may be good for another 29 years if I don't move any other gaskets, but a new filter would have been better.

For those of you that think the stock secondary filter is 2 microns, think again. Per the Westerbeke engineer I talked to it is 25 microns or larger. He recommended I continue to use the Wix or NAPA replacement which are 10u and a 10u filter in the Racor. He wanted the vast majority of the filtering to be done by the Racor.
 

Christian Williams

E381 - Los Angeles
Senior Moderator
Blogs Author
And for those of you who still have the original 30-year-old secondary filter, like Tom....

Yeah, I think Calder recommends a 10 on both engine and primary filters.

A two micron secondary may be overkill, but mine have never clogged. I change both filters very time, which is double overkill.

But I believe it is what James Bond would do.
 
Last edited:

Christian Williams

E381 - Los Angeles
Senior Moderator
Blogs Author
This video bears on the topic of fuel starvation, clogged filters and gunk in the tank.

Although inspection ports are nice to have, for many people with old boats I believe a dual-filter system, set up to allow filter changes with the engine running, would be an easy alternative.

https://www.youtube.com/watch?v=q1UgjkCZMV8
 

frick

Member III
If Your Secondary Filter Gets Wet

My friends Yanmar GM3 had a simular problem.
He had a small amount of water get through his RACOR and whetted his secondary fuel filter on the engine.... His diesel would not rev up until he changed the filter...

He also used a oil change pump to vacuum the water out of the bottom of his tank.

Rick
 

John McCarroll

Junior Member
It has been mentioned before, but my problem that was similar to yours troubleshot out to being a faulty Racor filter that had developed a crack in the aluminum housing and was letting air bubbles into the system. It was located by removing items from the system one by one and running the engine on a hose stuck into a bucket of diesel. I know from the earlier thread that I wasn't the only one that has had this problem. If you have an older Racor, look at it as suspect. If it has this problem, it will likely act differently when hot or cold. It doesn't take much to screw up the fuel system. :confused:

Good luck.
Wow, I had my diesel stall in 6 ft. Swells at night in a shallow channel, it was nerve wracking! It turned out that the racor was sucking air I think through a crack in the reservoir at the bottom. I ended up running without the racor for the last part of the trip. The new unit I have is for a Kubota tractor engine. Hope this one does the job for as long as the first! JM
 

mjsouleman

Sustaining Member
Moderator
Racor 15332_500FG_Turbine_Series

I had a fuel leak at the Racor Fuel/water separator.

This was the one item I did not replace when I replaced the fuel tank, lines and engine.

Retailer: Defender
Item: 15332_500FG_Turbine_Series
Cost: ~200

Note: the port sizes have changed from the earlier model and if you upgrade like me, you will have to find the appropriate brass reducer.
Specifications 500FG
Maximum Flow Rate:
60 GPH (227 LPH)

Port Size
3/4´´-16 UNF
(SAE J1926)

Service Clearance
Above Assembly
Below Assembly
5.0 in. (12.7 cm)
2.0 in. (5.1 cm)

Replacement Filters
2 micron
10 micron
30 micron
2010SM-OR
2010TM-OR
2010PM-OR

Water In Bowl Capacity
3.7 oz. (109 ml)

Height
11.5 in. (29.2 cm)

Width
5.8 in. (14.7 cm)

Depth
4.8 in. (12.2 cm)

Weight (dry)
4.0 lb (1.8 kg)

Max. Working Pressure
25 PSI (1.7 bar)

Clean Pressure Drop
0.25 PSI (1.7 kPa)

Water Removal Efficiency
99%

Ambient Temperature Range
(when fuel temp is)
-40° to +255°F (-40° to +121°C)
80˚ to 190˚F (27˚ to 88˚C)

MJS
 
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