Bleeding fuel system on the MD6A

groundhogyh · Apr 22, 2012

Hi,
THere is a screw on top of the fuel pump. Loosten and run electric fuel pump until fuel squirts out. Tighten.

I think I have read that actual fuel pump problems are uncommon.

If you wish to bleed further, partly unscrew pipe on top of injectors and run fuel pump and maybe turn over starter until you think all air is out and tighten.

groundhog

groundhogyh · Apr 22, 2012

sorry... I made a mistake...

CHange "screw on top of fuel pump" to
"screw on top of fuel filter"

gh

throbinkayla · Apr 22, 2012

So what about nature and the electric system.. or the system in general! Mother nature has mass power above all and has information that can't be shared! I sail on a secret of a many of islands. Dreams do come true its just reality that bites!

Sent from my Samsung Captivate(tm) on AT&T

groundhog groundhogyh@... wrote:

Vega1447 · Apr 22, 2012

Is fuel getting to injectors?
If not check high pressure pump - bleed bolt head on forward face of high pressure pump.
(Easy in my experience to get airlock here but also easy to clear. )
John V1447 Breakaway

John Kinsella
Mathematics and Statistics Dept
University of Limerick

Phone 0035361202148
Web jkcray.maths.ul.ie

vegatern · Apr 22, 2012

If the fuel tank has been moved up to a cockpit locker the engine may not have an electric fuel pump. In that case it is possible to bleed the fuel system by opening the bleed screw on the top of the primary filter and pumping the small lever on the feed pump ( follow the fuel line back from the filter to the small feed pump. It has the cone shaped cover) It takes a long time to push the fuel to the filter though. It is easier and much faster to install a primer bulb, the kind used on outboard motor tanks, between the fuel tank and your first filter, and pump the fuel with that.
Open the bleed screw on top of the filter and pump `till clean fuel flows. Do the same at the injector pump and then where the fuel line connects with the injectors.

Craig Tern #1519

bobnlesafloat · Apr 26, 2012

...fuel tank has been moved up to a cockpit locker the engine may not have an electric fuel pump...

This was set-up we had on Spring Fever and all we ever had to do to bleed the system - even from completely dry after running out of fuel - was to lift the decompression lever, spin the starter motor for 10 - 20 seconds, drop the decompressor and she fired/ran; I just wish our new boat's Yanmar was so easy!

vegatern · Apr 26, 2012

I will try to remember that. Thanks Craig

albinvega3283 · Nov 17, 2012

Hi Bob Carlisle or any one that can help.

My Vega 3283 is a Series 3 and has a Yanmar 2GM installed with the fuel tank in the port locker botttom. The engine starts fine and runs under load but when I increase the revs the engin e starts to hunt as if it is being starved of fuel. There is a primary filter fitted in the engine bay which is slightly higher than the engine fuel pump. A new engine fuel pump has been fitted. Any ideas a s to the cause of the problem and a solution please.

David Wisdish
Ponteneur V3283

pjacobs55 · Nov 17, 2012

David,
My suggestions:
1. Check tank and fuel to make sure it's squeeky clean.
2. Pull the tank dip tube and see if the end is clogged (some have a mesh screen).
3. Change all fuel filters (when the tank and fuel are clean).
4. Check all lines and connections for air leaks. (The "banjo" fittings on the Yanmar fuel system have a pair of copper washers to seal them, and sometimes loosen a bit, so snug them down. Be carefull as the bolts are hollow and can be snapped off if overtightened.)
5. Wash or replace the air intake filter.

If you're still having a problem you could pull the injectors and have them tested.

Good luck ... I hope you find the Gremlin causing the problem!
Peter
www.sintacha.com

winslowbuoy · Nov 17, 2012

Hi David - Is your bottom clean. Heavy fouling can cause poor running. Mike
________________________________
From: Peter peter@...
To: AlbinVega@yahoogroups.com
Sent: Saturday, 17 November 2012, 17:23
Subject: [AlbinVega] Re

iesel fuel flow to engine Yanmar 3GM

David,
My suggestions:
1. Check tank and fuel to make sure it's squeeky clean.
2. Pull the tank dip tube and see if the end is clogged (some have a mesh screen).
3. Change all fuel filters (when the tank and fuel are clean).
4. Check all lines and connections for air leaks. (The "banjo" fittings on the Yanmar fuel system have a pair of copper washers to seal them, and sometimes loosen a bit, so snug them down. Be carefull as the bolts are hollow and can be snapped off if overtightened.)
5. Wash or replace the air intake filter.

If you're still having a problem you could pull the injectors and have them tested.

Good luck ... I hope you find the Gremlin causing the problem!
Peter
www.sintacha.com

albinvega3283 · Nov 17, 2012

Hi Mike

Thanks for th thought.

Yes the bottom of the boat is clean and the diesel tank has been emptied and cleaned. The diesel is fresh and clean from a good source. The raw water intake is good and the raw water filter is clean and working efficiently.

Any more ideas please

David

From: MICHAEL FREEMAN
Sent: Saturday, November 17, 2012 9:05 PM
To: AlbinVega@yahoogroups.com
Subject: Re: [AlbinVega] Re

iesel fuel flow to engine Yanmar 3GM

Hi David - Is your bottom clean. Heavy fouling can cause poor running. Mike

________________________________
From: Peter mailto

eter%40sintacha.com
To: mailto:AlbinVega%40yahoogroups.com
Sent: Saturday, 17 November 2012, 17:23
Subject: [AlbinVega] Re

iesel fuel flow to engine Yanmar 3GM
David,
My suggestions:
1. Check tank and fuel to make sure it's squeeky clean.
2. Pull the tank dip tube and see if the end is clogged (some have a mesh screen).
3. Change all fuel filters (when the tank and fuel are clean).
4. Check all lines and connections for air leaks. (The "banjo" fittings on the Yanmar fuel system have a pair of copper washers to seal them, and sometimes loosen a bit, so snug them down. Be carefull as the bolts are hollow and can be snapped off if overtightened.)
5. Wash or replace the air intake filter.

If you're still having a problem you could pull the injectors and have them tested.

Good luck ... I hope you find the Gremlin causing the problem!
Peter
www.sintacha.com

albinvega3283 · Nov 17, 2012

Peter

Thanks for the list, it is a great help. Your view seems to be that the engine fuel pump should be man enough to lift the fuel from the tank and provide a good flow to the injectors. Is it likely that as the primary filter (a standard Delphi filter and water separator) is an inch or so higher than the lift pump that the head is too great for the lift pump?

Thoughts please

David

From: Peter
Sent: Saturday, November 17, 2012 5:23 PM
To: AlbinVega@yahoogroups.com
Subject: [AlbinVega] Re

iesel fuel flow to engine Yanmar 3GM

David,
My suggestions:
1. Check tank and fuel to make sure it's squeeky clean.
2. Pull the tank dip tube and see if the end is clogged (some have a mesh screen).
3. Change all fuel filters (when the tank and fuel are clean).
4. Check all lines and connections for air leaks. (The "banjo" fittings on the Yanmar fuel system have a pair of copper washers to seal them, and sometimes loosen a bit, so snug them down. Be carefull as the bolts are hollow and can be snapped off if overtightened.)
5. Wash or replace the air intake filter.

If you're still having a problem you could pull the injectors and have them tested.

Good luck ... I hope you find the Gremlin causing the problem!
Peter
www.sintacha.com

pjacobs55 · Nov 17, 2012

I hope it's not too great ... that's the way I just set up the Ballad.
The lift pump has to deliver to the top of the engine at the engine fuel filter and the injector pump. It's pushing fuel, so any leaks would be visible. But on the suction end of the pump, if any air is getting in, fuel delivery will be impaired somewhat and no leak will be visible. It sounds like one of those elusive problems that's more difficult to diagnose than repair!
Peter
www.sintacha.com

albinvega3283 · Nov 18, 2012

Hi Peter

Thanks for your knowledgeable input. You are like having a fairy godmother that has all the answers and a scorpion with a sting in the tail. I will begin my search for the lost leaks of Yanmar!

David

From: Peter
Sent: Sunday, November 18, 2012 5:30 AM
To: AlbinVega@yahoogroups.com
Subject: [AlbinVega] Re

iesel fuel flow to engine Yanmar 3GM

I hope it's not too great ... that's the way I just set up the Ballad.
The lift pump has to deliver to the top of the engine at the engine fuel filter and the injector pump. It's pushing fuel, so any leaks would be visible. But on the suction end of the pump, if any air is getting in, fuel delivery will be impaired somewhat and no leak will be visible. It sounds like one of those elusive problems that's more difficult to diagnose than repair!
Peter
www.sintacha.com

samr90us · Nov 18, 2012

David
You may want to check the fuel tank vent. I have run into similar problems with motorcycles that lived outside. If the tank vent is partially clogged it will be OK at low RPM but will cause a vacuum when there is more suction. Good luck..... Sam

albinvega3283 · Nov 18, 2012

Sam

Thanks for the valuable input, I will check the vent.

David

From: samr90us
Sent: Sunday, November 18, 2012 3:58 PM
To: AlbinVega@yahoogroups.com
Subject: [AlbinVega] Re

iesel fuel flow to engine Yanmar 3GM

David
You may want to check the fuel tank vent. I have run into similar problems with motorcycles that lived outside. If the tank vent is partially clogged it will be OK at low RPM but will cause a vacuum when there is more suction. Good luck..... Sam

Vega1447 · Nov 19, 2012

Maybe a vent issue with the fuel tank?

pelagicasd · Nov 23, 2012

A slow air leak into the system could also cause the engine to stop. Lyric has an electronic pump in line in addition to the engine pump. We started having problems and I suspected that the diaphragm may have developed a leak. We changed the pump and stopped the problem. It might be worthwhile to check for loose fittings between the injectors and the tank. Maybe a bad gasket on the fuel filter? Good luck! Walt
To: AlbinVega@yahoogroups.com
From: carrico@...
Date: Mon, 19 Nov 2012 14:12:58 -0500
Subject: Re: [AlbinVega] Re

iesel fuel flow to engine Yanmar 3GM

Maybe a vent issue with the fuel tank?

Trevykins · Nov 23, 2012

Hi gang - lesson # 3002 - never allow the hoist operator to lift your boat by the prop shaft. Has anyone got a spare used shaft/control tube? Many thanks in advance. Trevor (V2915 - Mystic Rose)