Advice needed - Volvo MD2020 won't start

southcoaststeve

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Hi,
I'm after a bit of advice, I have a Volvo MD2020B and it has decided that starting is no longer an option.
I have had the injectors and fuel injector pump refurbished, fuel is getting to the inlet side of the injectors (unions cracked and cranking on the start button gives spurts of fuel at the union)
Injector unions were tightened while still spinning over the engine and the engine is spinning over well, but simply won't fire, it sounds like it is trying to, but not catching.
Where should I be looking next? Valve timing? Exhaust elbow blockage?

Help..
 

TSB240

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I would check the glow plug relay in the black box on the side of the engine. Is actually working? If you take the lid off wiggle it about and keep a finger on it when you preheat. You should see the lights dim on your engine control panel and the relay will click. Very common problem with poor starting on the MD20x0 series engines. Caused by vibration and corrosion of the contacts and can give correct voltage but minimal current to glow plugs... Contact cleaner and also wedge the relay in with some padding to the lid.
 

Neeves

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I would check the glow plug relay in the black box on the side of the engine. Is actually working? If you take the lid off wiggle it about and keep a finger on it when you preheat. You should see the lights dim on your engine control panel and the relay will click. Very common problem with poor starting on the MD20x0 series engines. Caused by vibration and corrosion of the contacts and can give correct voltage but minimal current to glow plugs... Contact cleaner and also wedge the relay in with some padding to the lid.

And also try bending the relay blades slightly.

Checking the exhaust elbow is quite easy. Simply remove the 4 nuts holding the elbow to the block and slide off. it is obvious, as soon as you remove it, if there is an issue. Ours last about 1,000hrs.

Jonathan
 

Cantata

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Pardon me for asking but are you sure the stop knob/cable is pushed all the way in? On my 2020 it only needed to be out a fraction of an inch to prevent the engine from starting.
 

peter gibbs

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If the valves are not seating well - easy season itis - you may try squirting oil in the air intake when cranking. Do shut off raw water intake when doing this (just for a few seconds) to prevent seawater flooding engine.

PWG
 

southcoaststeve

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Thought I'd update this for posterity now that the engine is working..

Valve clearances checked and tweaked - no difference
Compression tested - cylinders 2 & 3 both at 390, cylinder 1 at 250
put oil into inlets and spun over, compression increased to 450,450 and 300 respectively, however the oil was ejected out of the inlet of number 1 while compressing.

Cylinder head off and found the valve seat faces were all very corroded, the head gasket also seemed to be passing between 2 & 3, new valves, lapped in, new gaskets and re-assembled resulted in a happy engine, fired up and runs a dream.
 
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