Cold Start Problem on Volvo MD11

LadyStardust

LadyStardust

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14 Oct 2004
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159
Location
Chiapas, Mexico
sistermidnight.co.uk
My cold start button will not stay down on my Volvo MD11 Engine.
Currently the engine is taking 30secs to start, I have had the injectors and the Injector pump serviced, Compression is like new, fuel is there, airway and exhaust seem clear so I'm assuming the cold start mechanism is affecting the start. Once the engine starts it runs perfectly and will start straight away if stopped. The button used to stay down; I give it full throttle before trying to depress it. The service manual I have is not a lot of use.
Does anyone have any ideas, or any details on how the mechanism works? Ideally a diagram would be great. As usual it is in a most inaccessible place.

Cheers,
 
I've got the original Volvo Penta Workshop manual for the MD11C and MD17C (I've got the 17). I've just had a quick scan through but can't see anything about the cold start, the 17 has an automatic device.
Where is the button situated, give me a clue and I'll have another look!
 
The cold start button should stay down when pressed. If this doesn't happen or it releases early it's a sign of wear (surprise surprise, it's not a new engine by any means). Personally I doubt if there are any spares available.

I'd epoxy a piece of metal to the button and keep it pressed down until the brute fired if it were mine.
 
Thanks for the email Tommyrot, sadly that is the same manual as I have and as you say, it doesnt help much.

The button is right by the injection pump, aft of the cylinders.
it did feel like wear as it got harder to keep it down each time, but an engineer has looked at it and thinks it may not be linking in to the pump/rack properly, however without understanding how it connects it's hard to know what to do. We could lift the engine out to get access to that area easily, but then i would be tempted to put a new engine in after all that work.
 
On the MD2B, precursor of the MD11, there is a plate on the back of the crankcase held on by 3 bolts. If you remove this you get access to the rack and starting button. You should open the throttle fully and then push the cold start button down. When the engine starts you dethrottle to stop it racing and this disconnects the cold start button and it jumps up. I think that you will find that when you push it down it is not catching under the rack, either because the rack or the button are worn, or perhaps gunge has filled the ridge in the cold start button which catches under the rack. I suggest you examine the workings of the mechanism through the aperture with a mirror and see if you can work out what is wrong. On one occasion the cold start button on my engine got caught the wrong side of the rack and the engine petered out. Once I sussed out what was wrong, it only took a moment to get the cold start button back in place and away it went. Good Luck
 
Depressing the cold start on a Volvo MD allows the fuel rack to travel further thn normal with the maximum movement controlled by an adjuster screw under the asymetrical shaped plate on the rear of the engine near the fuel pumps.

The cold start includes a spacer which further limits the fuel rack movement under normal running.

If the cold start refuses to stay down then this indicates that the fuel rack is not moving fully to the cold start,excess fuel position. This may be due to wear or gunge on the fuel pump body and or rack. Although this could be cleaned and freed in situ there would be a risk of getting too much WD 40 etc into the sump oil so the best way is to lift the fuel pump out and clean and free the rack.

This must be carefully done as there is a bronze block on the governor arm where it engages the rack which is EASILY lost into the sump if the pump is not withdrawn cleanly and carefully.

Re installing the pump also has to be carried out with care to engage this block correctly.

Sometimes working the throttle from full to off with the cold start button depressed will help free the rack!!!!!

The problem is that this is a cooler part of the engine and so there is a risk of sludge and rust forming around these links if the engine isnt run to full temperature.
 
"I doubt if there are any spares available"

First call for all things old Volvo has to be J Hawkins Marine at Rochester 01634 840812. Very knoowledgeable and helpful.

Regards, Mudhook.
 
Paul,

If you cannot sort out the problem, don't go throwing any money at it. I have my old MD11C engine sitting in my workshop at home and the cold start mechanism was working fine when I lfted it out of my boat (bearings had gone). If you can wait a few weeks until I get home, I can strip down the bits you need and get them to you.
 
I had the same problem on my MD1B engine, after the winter lay-up. I removed the inspection plate on the rear of the engine, just below the cold start button, to try to see what was wrong, and after a bit of fiddling with it, it started working again. I didn't actually do anything to fix it - it just seemed to have been gummed up after the winter. If yours has a similar inspection plate, I would try removing it and have a bit of a poke around inside. Good Luck!!
 
If you cannot sort the problem quickly then try the alternative cold start method which is
1. Get a oil can with a flexible nozzle
2. Prime it so the oil is at the tip
3. Remove the air filter and get the oil can nozzle right into th engine air inlet
4. Put put ONE or TWO good squirts of engine oil into the cylinder
5. Withdraw the oil can replace the air filter and start
6. Mine always started first time with this method even when compression was low or fuel in short supply
Do not overdoo the oil as it is not compressible
cheers
Martin
 
Might have to send the fuel pump as this with associated rack is an important bit of the process and the problem could be a sticking rack if it isn t just the adjuster screw needs backing of a wee bit.


John
 
You don't make it clear whether the button just pops straight back out again, or whether it stays down for a while. I am surprised that you would be trying to start the engine on full throttle, anyway. The procedure I used to use was:-

1. Set throttle to about 30%
2. Depress cold start which then stays in
3. Crank, and throttle back once revs climb, keeping revs to around 1800 but make sure that charging has started. The cold start jumped out immediately the engine started.

I don't know whether the cold start would stay in on full throttle - I never tried it /forums/images/graemlins/shocked.gif
 
could start buttom picture

Could anyone post a picture from the location of the cold start buttom, i have recently purchased a boat with the md11c, and i haven't heard about the buttom till now, on the manual i did not find any indication.
I am also having a problem with the flywheel that is stuck and doesn't run free as it did some time ago, when i first saw the boat.
It could be moved with hands.
So i can't put the motor working as the flywheel is stucked.
Any clues or hints on what sort of problem does it have?
sorry for the bad english.
Kind regards from Portugal!
 
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