Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 20-11-2015, 08:23   #1
Senior Cruiser
 
mikereed100's Avatar

Cruisers Forum Supporter

Join Date: Dec 2005
Location: Santa Barbara
Boat: 46' custom cat
Posts: 1,571
Images: 2
Interesting diesel problem

One of my Nanni 3.30's has developed an "interesting" quirk. It will fire right up, run for several seconds, then die. After some extended cranking over it will start again and run flawlessly all day. The next the the process repeats.

This all began one month ago when I ran out of fuel. I added more fuel, bled the system and it fired right up. The next day the above problem began.

At first I assumed that the filters had become clogged by crap at the bottom of my fuel tank, but after replacing both primary and secondary filters the problem remains unchanged.

If I bleed the system the problem is solved, until I try to start it a second time. It seems obvious that air is getting into the system and I have checked and rechecked the fuel filter attachments but I don't believe that is where the problem is. My next move is to go through the system and check every connection, but I cannot figure out why running out of fuel would have caused this problem. Any words of wisdom?
__________________

__________________
Mike

www.sailblogs.com/member/rumdoxy

Come to the dark side. We have cookies.
mikereed100 is offline   Reply With Quote
Old 20-11-2015, 08:47   #2
Registered User
 
Snore's Avatar

Join Date: Jan 2011
Location: St Petersburg
Boat: Tartan 33
Posts: 1,880
Interesting diesel problem

The way I found mine--- bleed the engine and get it running. Turn off the engine and place paper towels under fuel line.

Wait a day. Wherever there are wet spots on the towels, there are leaks. Odds are it is on the vacuum side of the lift pump.


Sent from my iPhone- please forgive autocorrect errors.
__________________

__________________
"Whenever...it requires a strong moral principle to prevent me from deliberately stepping into the street, and methodically knocking people's hats off- then, I account it high time to get to sea..." Ishmael
Snore is offline   Reply With Quote
Old 20-11-2015, 09:36   #3
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 17,037
Re: Interesting diesel problem

Called loss of prime, very common, usually an air leak, but seeing as how yours occurred after running out of fuel , I bet you still have air in there somewhere.

On edit, it's definitely on the suction side, or almost certainly anyway, what kind of pump did you use to bleed it? Often that is the source of an air leak, a leaking pump and or bleed screw
__________________
a64pilot is offline   Reply With Quote
Old 20-11-2015, 13:55   #4
Registered User

Join Date: Mar 2011
Location: The Netherlands
Boat: Victoire 1122
Posts: 107
Re: Interesting diesel problem

Had similar problems because of a missing seal-ring in a system that had the fuel-tank beneath the engine. Gravity pulled air into the system, fuel ran back into the tank.
Check every fuel line-connection very carefully.
__________________
aluijten is offline   Reply With Quote
Old 20-11-2015, 14:24   #5
Certifiable Refitter/Senior Wannbe
 
Wotname's Avatar

Cruisers Forum Supporter

Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: Van DeStat Super Dogger 31'
Posts: 7,331
Re: Interesting diesel problem

Quote:
Originally Posted by mikereed100 View Post
One of my Nanni 3.30's has developed an "interesting" quirk. It will fire right up, run for several seconds, then die. After some extended cranking over it will start again and run flawlessly all day. The next the the process repeats.

This all began one month ago when I ran out of fuel. I added more fuel, bled the system and it fired right up. The next day the above problem began.

At first I assumed that the filters had become clogged by crap at the bottom of my fuel tank, but after replacing both primary and secondary filters the problem remains unchanged.

If I bleed the system the problem is solved, until I try to start it a second time. It seems obvious that air is getting into the system and I have checked and rechecked the fuel filter attachments but I don't believe that is where the problem is. My next move is to go through the system and check every connection, but I cannot figure out why running out of fuel would have caused this problem. Any words of wisdom?
Running out of fuel didn't cause the problem as such; IMO the problem was caused when you bled the system. Somehow you just got something a tiny bit wrong when you bleed it and the problem is repeating itself every time you re-bleed it.

Maybe one bleed point is not fully sealing or maybe you disturbed a flexible fuel line joint or something that was touched after running out of fuel.

Looking coldly at the facts; all was good until running out of fuel. After that you disturbed the fuel supply line by bleeding (because you had to, of course). Now you have a problem that is classically a very small air leak.

Presumably you have a vacuum fuel line rather than a pressure system i.e. you lift fuel up from the tank rather than have a gravity delivery form the tank.

If the leak remains elusive, a long winded approach is to remove the line from the tank pickup and pressurise this line by whatever means available and search for fuel or air escaping rather than air entering.

I suppose you could pressurised the system by connecting a air compressor or such into the fuel tank vent but go carefully with the pressure!!!!
__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Wotname is offline   Reply With Quote
Old 20-11-2015, 14:36   #6
Registered User

Join Date: Nov 2015
Location: Kemah
Boat: Herreshoff Prudence design #71
Posts: 11
Re: Interesting diesel problem

Check your copper washers on the fuel line bleed points. They can only be crushed so many times before they wear out. Buy some new ones if there available locally. If not you can remove the old ones and if they do not have any radial defects in them you can heat them up red-hot with a lighter and quench them in a glass of water. This will allow them to be compressed again. Just do it away from the engine bay and hold the washers with a pair pillars or small wire.
Oh and watch out they will be hot.


(radial defects are defects that extend from the inner circle to the outer circle across the gasket seating surface)


This happened to me last week on my really old YANMAR
__________________
t140frank is offline   Reply With Quote
Old 20-11-2015, 14:39   #7
Registered User

Join Date: Nov 2013
Location: Nice, France
Boat: Hunter Marine 38
Posts: 281
Re: Interesting diesel problem

Please check the pickup tube in the tank. It is possible there is crud accumulated on the mesh at the bottom of the tank. This crud can get compressed by the suction, starving the engine. Since you ran dry there can be an important crud accumulation on this mesh.


Envoyé de mon iPad à l'aide de Cruisers Sailing Forum
__________________
sailormed is offline   Reply With Quote
Old 20-11-2015, 15:11   #8
Certifiable Refitter/Senior Wannbe
 
Wotname's Avatar

Cruisers Forum Supporter

Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: Van DeStat Super Dogger 31'
Posts: 7,331
Re: Interesting diesel problem

Quote:
Originally Posted by t140frank View Post
Check your copper washers on the fuel line bleed points. They can only be crushed so many times before they wear out. Buy some new ones if there available locally. If not you can remove the old ones and if they do not have any radial defects in them you can heat them up red-hot with a lighter and quench them in a glass of water. This will allow them to be compressed again. Just do it away from the engine bay and hold the washers with a pair pillars or small wire.
Oh and watch out they will be hot.


(radial defects are defects that extend from the inner circle to the outer circle across the gasket seating surface)


This happened to me last week on my really old YANMAR
This good advice!

All you are doing is re-annealing the copper to make it soft again as cooper does work harden reasonably quickly. Unlike annealing say steel, copper can be cooled quickly although I think you do get it slightly softer if it is left to cool naturally.

FWIW, I now keep a spare set of all the various copper washers on the engine and I replace them every time I disturb one. The one taken off is re-annealed as described t140frank and becomes the new spare.
__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Wotname is offline   Reply With Quote
Old 20-11-2015, 15:13   #9
Registered User

Join Date: Oct 2009
Location: australia
Posts: 467
Re: Interesting diesel problem

Try.
1. Blow back through fuel line, pickup mesh may be clogged.


2. Replace or Anneal all bleed screw crush washers as previously by Frank.


3. Before next shut down cover every joint, threaded fitting and bleed point with a thick blob of grease, do not forget shut off valve spindle. Using this system will help isolate the problem.
__________________
shakey doug is offline   Reply With Quote
Old 20-11-2015, 15:18   #10
Certifiable Refitter/Senior Wannbe
 
Wotname's Avatar

Cruisers Forum Supporter

Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: Van DeStat Super Dogger 31'
Posts: 7,331
Re: Interesting diesel problem

Regarding the pick up mesh.
The fault description given by the OP - It will fire right up, run for several seconds, then die. After some extended cranking over it will start again and run flawlessly all day. The next the the process repeats - does not support crud getting lodged there.

But then again, strange stuff happens from time to time
__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Wotname is offline   Reply With Quote
Old 20-11-2015, 15:28   #11
Registered User

Join Date: May 2012
Posts: 466
Re: Interesting diesel problem

The fact that it runs for only a few seconds tell you that the leak is on the engine very close to the injection pump
__________________
sartorst is offline   Reply With Quote
Old 20-11-2015, 16:01   #12
Registered User
 
DumnMad's Avatar

Join Date: Mar 2012
Location: Nelson NZ; boat in Brisbane
Boat: 45ft Ketch
Posts: 1,246
Re: Interesting diesel problem

I'd go for the copper washers or junk/water in the fuel lift pump.
__________________
DumnMad is offline   Reply With Quote
Old 27-11-2015, 13:47   #13
Senior Cruiser
 
mikereed100's Avatar

Cruisers Forum Supporter

Join Date: Dec 2005
Location: Santa Barbara
Boat: 46' custom cat
Posts: 1,571
Images: 2
Re: Interesting diesel problem

Thanks for all the replies and excellent suggestions! We have been under way down the coast of Baja and I have not yet had time to delve too deeply into this as I have been busy fixing all the other stuff I'm breaking, but will certainly recheck all my connections and try pressurizing the system and roasting the copper washers if that doesn't work.
__________________
Mike

www.sailblogs.com/member/rumdoxy

Come to the dark side. We have cookies.
mikereed100 is offline   Reply With Quote
Old 27-11-2015, 14:40   #14
Guy
Registered User

Join Date: Feb 2013
Location: So. Oregon, USA
Boat: Seafarer36c
Posts: 4,308
Re: Interesting diesel problem

[QUOTE=Wotname;1967263]
I think you do get it slightly softer if it is left to cool naturally.

Not how I remember it. Until I made it to the big league, we would anneal all the gaskets when we cleaned spark plugs. You put a string of them on a steel rod, heat them dark red one at a time and knock them off into a bucket of water as soon as possible. If you got them to the right temp and cooled them quickly enough they would look all clean and new. The big league uses new gaskets.
__________________
Guy is offline   Reply With Quote
Old 27-11-2015, 15:07   #15
Senior Cruiser
 
senormechanico's Avatar

Cruisers Forum Supporter

Join Date: Aug 2003
Boat: Dragonfly 1000 trimaran
Posts: 5,826
Re: Interesting diesel problem

I agree with Guy.
Had a leak which turned out to be a copper washer on a banjo fitting.
Heated it red hot and dumped it into a glass of water.
Reassembled and no leak.
__________________

__________________
Memento,homo, quia pulvis es, et in pulverem reverteris.
senormechanico is offline   Reply With Quote
Reply

Tags
diesel

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Cal 34s - Interesting Reports Jim H Monohull Sailboats 13 17-10-2011 12:23
interesting news GordMay The Library 3 21-04-2005 12:35
Interesting Projects in Brazil sinbad7 Atlantic & the Caribbean 1 21-06-2004 05:21
Interesting Article GordMay Boat Ownership & Making a Living 0 08-08-2003 09:18
Interesting link for the LiveAboards? Gisle Liveaboard's Forum 2 04-04-2003 22:18



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 01:04.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.