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10-09-2015, 17:43
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#1
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Registered User
Join Date: Mar 2015
Location: Fulton, Tx
Boat: Pearson 323
Posts: 4
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Volvo D1-30F Regulation System Problem?
I have purchased a boat with a near new Volvo Penta D1-30F engine that has been giving me problems. When I had the boat surveyed I was told to have a mechanic look at it since it insisted on idling around 2000 RPMs. I complied and $400 later was told the motor had set too long and needed to be taked out and run to clear the injector pump and loosen any centrifugal weights that might be sticking. I bought the boat and motored/sailed it from Kemah, Tx to Fulton, Tx which took four days. During the trip the motor kept dying and the maximum RPMs I could reach without the motor dying kept getting lower. When I got to Fulton I changed the Racor water separator filter, polished the remaining fuel, and she will run up to her rated RPM now. But she still wants to idle high.
When first started she will idle at ~800 RPMs for a few seconds and then she slowly climbs to her ~2000 RPM area. During this time the throttle is as low as it can go and the throttle lever is against the idle adjustment bolt, which is backed out almost all the way. I want to check with some experience before I start making any adjustments. I think it has something to do with the regulation system. I will attach a picture of the regulation system, and does anyone know what the adjustment screw #33 adjusts?
Thanks,
Randal
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11-09-2015, 13:49
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#2
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Registered User
Join Date: Nov 2013
Location: Slidell, La.
Boat: Morgan Classic 33
Posts: 2,845
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Re: Volvo D1-30F Regulation System Problem?
The mechanics' suggestion of sticking governor weights seems to make sense, the idea of pulling the engine to fix it seems like a last resort kind of thing. I'd try changing the oil with maybe some type of lubrication system cleaner.
Not sure about item 33, but it looks like the factory-set high speed governor control, if so, it shouldn't be messed with (unless somebody else did before you got there). There are people here that do know, maybe someone will chime in...
In case you don't have one, there's a copy of the service manual here:
http://j109.org/docs/volvo_d1-30_workshop_manual.pdf
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11-09-2015, 15:31
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#3
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Registered User
Join Date: Mar 2015
Location: Fulton, Tx
Boat: Pearson 323
Posts: 4
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Re: Volvo D1-30F Regulation System Problem?
Thanks Jim. I have that service manual along with a newer one, but neither say much about the regulation system. And I agree, I don't need to adjust anything until I have a clear understanding what it does. Something that does have me kinda puzzled, when in gear (slightly loaded) the motor idles normally. But when in neutral it wants idle high. How do those weights on the from of the cam shaft know whether the motor is loaded or not? In my mind they should only sense the RPMs of that cam shaft?
Thanks,
Randal
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11-09-2015, 16:32
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#4
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Registered User
Join Date: Nov 2013
Location: Slidell, La.
Boat: Morgan Classic 33
Posts: 2,845
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Re: Volvo D1-30F Regulation System Problem?
I'm not very clear about that myself, but I think it has to do with the fact that speed is controlled by the amount of fuel being injected. If I understand correctly, the weights can't really be taken into account by themselves: the governor is a fuel control system with set initial parameters. When the engine is running at a certain speed at a certain fuel setting, a change in load either increases or decreases speed, which changes the amount of fuel injected, which changes the speed up or down to match the load.
Realize that doesn't tell much so here's an old (1942 no less) video that explains some basics. I assume they've refined things a lot since then though...
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11-09-2015, 21:43
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#5
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Registered User
Join Date: Jul 2012
Location: Auckland New Zealand
Boat: Farr 1020
Posts: 104
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Re: Volvo D1-30F Regulation System Problem?
Randal
The governor only sees the speed of the cam shaft that drives it, there is no link to engine load. The governor is a fly-ball governor linked to a fuel control rod (FCR) that operates inside a fuel control sleeve (FCS). The throttle lever changes the position of the FCS such that for increasing speed it will allow more fuel to be delivered to the injectors. As a result the fly-ball weights of the governor open up and change the position of the FCR which moves to compensate the sleeve change and maintain the new speed requirement.
In your case where the idle speed drops to 800 rpm when you put into gear but will go back to 2000 rpm when you put it back in neutral indicates to me that there is sticktion in the governor linkage or possibly a broken spring in one of the governor weights.
Once you have the understanding then you know what you are looking for if you need to open the case to examine the governor. However I would be trying some governor exercising before going this far first. That is some rapid throttle full throttle openings and closings to exercise the internal mechanisms of the fuel feed through the FCR/FCS relationship
At this stage I would guess that it is sticktion in the mechanism from lack of use rather than any breakage preventing the governor from responding accurately.
Cheers
Acushla
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12-09-2015, 04:27
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#6
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Registered User
Join Date: Nov 2013
Location: Slidell, La.
Boat: Morgan Classic 33
Posts: 2,845
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Re: Volvo D1-30F Regulation System Problem?
Quote:
Originally Posted by Acushla
Randal
The governor only sees the speed of the cam shaft that drives it, there is no link to engine load.
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I'm confused. If there's no link to engine load then what is the governor governing?
That is of course a rhetorical question, no need to answer. Suggest you have a look at the video for a basic understanding of some of the dynamics involved.
The ability of a combustion engine to do work is directly related to its ability to burn fuel efficiently. The ability to burn fuel efficiently is derived from having the correct ratio between air (oxidizer), fuel, and load. For a mechanically governed diesel engine, these ratios are defined by the governor, and specified by throttle position.
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12-09-2015, 04:39
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#7
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Moderator and Certifiable Refitter
Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: C.L.O.D.
Posts: 20,301
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Re: Volvo D1-30F Regulation System Problem?
Quote:
Originally Posted by jimbunyard
I'm confused. If there's no link to engine load then what is the governor governing?
That is of course a rhetorical question, no need to answer. Suggest you have a look at the video for a basic understanding of some of the dynamics involved.
The ability of a combustion engine to do work is directly related to its ability to burn fuel efficiently. The ability to burn fuel efficiently is derived from having the correct ratio between air (oxidizer), fuel, and load. For a mechanically governed diesel engine, these ratios are defined by the governor, and specified by throttle position.
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Hmm… AFAIK the governor tries to govern RPM, not load. It does so by allowing more or less fuel into the engine. The air is determined solely by RPM.
But this could be BS
Maybe I should watch the video again...
__________________
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
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12-09-2015, 05:03
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#8
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Registered User
Join Date: Jun 2009
Location: BVI
Boat: Leopard 40 (new model)
Posts: 1,385
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Re: Volvo D1-30F Regulation System Problem?
Quote:
Originally Posted by rfwilliams
Thanks Jim. I have that service manual along with a newer one, but neither say much about the regulation system. And I agree, I don't need to adjust anything until I have a clear understanding what it does. Something that does have me kinda puzzled, when in gear (slightly loaded) the motor idles normally. But when in neutral it wants idle high. How do those weights on the from of the cam shaft know whether the motor is loaded or not? In my mind they should only sense the RPMs of that cam shaft?
Thanks,
Randal
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Somewhere there is a device that sets the minimum rate of fuel flow (as opposed to the main governor device that adjusts flow based on actual rpm vs rpm you want as per throttle position). That rate is more than what is required without load. Fix that and you are done.
Sent from my GT-I9192 using Cruisers Sailing Forum mobile app
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12-09-2015, 05:42
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#9
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Moderator Emeritus
Join Date: May 2008
Location: Fort Lauderdale, FL
Boat: 48 Wauquiez Pilot Saloon
Posts: 5,975
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Re: Volvo D1-30F Regulation System Problem?
Dang... Again???
2 posts, and nobody says WELCOME to CF!
Randal, I go with busted gov spring too, but the linkage that the weights move can get sticky... I have NO IDEA about the exact mechanism for your Volvo...
I've also had the throttle position linkage INSIDE the IP stick... That's sometimes not a direct linkage, but also actuated by a spring...
I wish I had intricate knowledge of these particular innards but I don't... Seems the good lord has blessed me with the knowledge gained from the other bazzillion pumps I've had apart against my will...
AND!!!
What kinda boat (new toy) did ya get?
__________________
In the harsh marine environment, something is always in need of repair...
Mai Tai's fix everything...
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12-09-2015, 13:13
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#10
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Registered User
Join Date: Mar 2015
Location: Fulton, Tx
Boat: Pearson 323
Posts: 4
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Re: Volvo D1-30F Regulation System Problem?
Quote:
Originally Posted by HappyMdRSailor
What kinda boat (new toy) did ya get?
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She is a 1981 Pearson 323, and thanks for asking HappyMdRSailor.
Thank you all for the replies, and thank you Jim for the video link. It makes a lot of sense, and I am trying to get a mental grasp of what is going on. It seems to me that, at a set throttle position, the governors job is to maintain a certain RPM. This means when the motor load changes up or down, and the motor want to speed up or slow down because of the change in load, the governor changes the flow of fuel to maintain the RPM as originally set by the throttle lever at a set load. If this is true, then when the motor is driving the boat and boat runs into an opposing current (motor load) the motor will try to slow - the governor will allow more fuel to the motor, and the RPM will be maintained. I believe this is working correctly with this motor. She motors fine, and I am at fault for not making this clear initially. Her problem is the idle.
I am not certain about anything, but I am leaning towards the idea svlamorocha has presented. If the governor works correctly under load at 2000 RPMs, but cannot maintain an idle speed with the throttle lever as low as it can be moved, then it might be another part of the regulation system that is at fault. A larger view of the D1-30F regulation system calls item #20 a governor. I have attached another diagram with this part number named. I have also attached a diagram out of the workshop manual that calls the weight system on the cam shaft gear the 'centrifugal governor'. It is the first governor #20 that I think might be adjusted with the adjustment screw #33.
Any ideas?
Thanks,
Randal
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17-10-2015, 05:31
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#11
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Registered User
Join Date: Mar 2015
Location: Fulton, Tx
Boat: Pearson 323
Posts: 4
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Re: Volvo D1-30F Regulation System Problem?
I have looked through the lower motor oil filler cap opening with a dental mirror and it appears to me that the two springs that operate the regulation system are intact and stretch when the throttle lever is actuated, or the fuel control lever is moved forward. .
Another thing I would like to ask is, if the return fuel line was clogged, what would the symptoms be?
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