Volvo MD1B won't start

Kyle2

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Volvo MD1B won\'t start

My Volvo MD1B engine won't start. I wonder if there is a problem with the fuel injection. The cold start button on the injector pump will not stay down when pressed. Could this be a symptom of something wrong with the injector pump? Both bleed screws emit fuel when loosened, so supply to the injector pump should be OK.
 

Pierrot

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Re: Volvo MD1B won\'t start

I don't see how a problem with the injection would affect the cold start button. AFAIK that is only affected by the throttle position and the temp of the engine; so probably worth making sure that the throttle cable is still well adjusted so that you can open the throttle almost full before starting.

In my experience it is virtually impossible to get my MD2B to start from cold without using the Cold Start button. However if it won't stay down you can hold it in by hand and try it that way.
 

Stemar

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Re: Volvo MD1B won\'t start

As I recall, from my MD1 (RIP), the button will only stay down if the throttle is fully open. Have you checked that the throttle is opening when you move the lever, and that it's going all the way?

My one was a good starter, but also only with the button down if cold.

If fuel was getting to it, as my engine turned over before starting, the injector gave a little chirp sound at the top of each compression stroke.

HTH
 

scarlett

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Re: Volvo MD1B won\'t start

I had a MD1 and it definitely would not start unless the cold start button was down.

The cold start button is as I recall on the injector pump and raised when the engine runs, by the engine speed lever being advanced. I suspect it is a purely mechanical arrangment rather than engine speed dependent and this would be the area I would investigate first.
 

Kurrawong_Kid

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Re: Volvo MD1B won\'t start

The cold start button is not directly part of the injection pump. When pushed down it presses against an arm which increases the fuel supply by moving the "rack" (which controls the fuel supply to the pump) further forward. As stated in earlier posts this cold start button will only stay down if more than half throttle or so is set. When the engine revs, the governor should throw the cold start button up, or it will come up as you throttle back to avoid "racing".
As a first step I suggest you take off the plate which is on the back of the engine by the cold start button and check that the cold start arm is not seized and is therefore not advancing the "rack". I once had the cold start button go behind the arm, which stopped the engine.It might be that. With the plate off and the throttle well open, you should see the arm make a sudden movement when you push the cold start button down.
The workshop manual doesn't say any thing about all this! If you do get some movement, then check that the throttle arm is not seized, which would explain why the cold start button will not stay down.
 

Kyle2

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Re: Volvo MD1B won\'t start

Many thanks. I have removed the plate you describe at the back of the engine and managed to get the cold-start button working properly again. The engine has now started!!
 
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