Volvo Penta MD2030 Starting Problem

[Sealong]

Hello all,
My MD2030 is becoming difficult to start. The injectors were serviced about 50 hours ago and I replaced the glow plugs and relay at the same time. Yesterday, I changed the (two) fuel filters, they were clean with no sign of any form of residue, as was the glass filter bowl.

It will typically take two or three 30 second sessions of cranking it over before it starts. However, once started it runs and idles perfectly. There is voltage across the glow plugs and they draw current.

Any suggestions as to a likely cause would be much appreciated.
Chris

 

[Just_sayin']

I can’t help with the starting problem but be careful cranking for up to 90 seconds.

The impeller is drawing water in that is not being expelled by the exhaust gasses.

You can actually fill the exhaust system with seawater to the point where it fills the cylinders through the exhaust valves.

The resultant fluid lock is normally disastrous.

 

[Boater Sam]

Any exhaust smoke when its cranking?

Have you checked the compressions?

Have you set the tappets?

 

[yotter]

I can’t help with the starting problem but be careful cranking for up to 90 seconds.

The impeller is drawing water in that is not being expelled by the exhaust gasses.

You can actually fill the exhaust system with seawater to the point where it fills the cylinders through the exhaust valves.

The resultant fluid lock is normally disastrous.

Indeed, be careful, best to shut the coolant water inlet seacock if cranking for more than a few seconds and then open it when the engine starts. I managed to fluid lock my 2030 by not doing this, fortunately I was lucky and after expelling the water from the cylinder(s) there was no long term damage

 

[Bobc]

Sounds suspiciously like compression issues to me

 

[Never Grumble]

Where did you get your glow plugs from just that I bought some from parts 4 engines just over a year ago and they turned out to be a defective batch, the ends burnt off. Of course you might not have bought from there.

 

[Neeves]

Hello all,
My MD2030 is becoming difficult to start. The injectors were serviced about 50 hours ago and I replaced the glow plugs and relay at the same time. Yesterday, I changed the (two) fuel filters, they were clean with no sign of any form of residue, as was the glass filter bowl.

It will typically take two or three 30 second sessions of cranking it over before it starts. However, once started it runs and idles perfectly. There is voltage across the glow plugs and they draw current.

Any suggestions as to a likely cause would be much appreciated.
Chris

There are 2 identical relays, swap them round. The relays are notorious for developing poor electrical contacts and your engine is quite old now. Check and check again (though I do note you have done all of this).

I hate to mention this (as I have a current thread on the topic) - have you checked the exhaust elbow. When the engine is running can you achieve the same maximum revs as you did some time ago. If the elbow is restricted it will be difficult to start and will not achieve full power (don't know what full power is for a 2030).

Jonathan

 

[yotter]

If correctly propped, engine should rev to approx 3400 under load.

 

[QBhoy]

Hi. Fresh oil will help. If your oil is thin or diluted with diesel from previous injector issues, you’ll lose loads of compression and she will be less reluctant to fire.

 

[lustyd]

Just went through exactly this with my MD2040, the answer is probably starter. The issue seems to stem from either a low battery or bad connection (really, REALLY check your connections, often there's green paint in the way!). The low voltage causes higher amps which causes heat which causes the starter to deteriorate, effectively making it less powerful. The lack of power then translates to your engine being difficult to start despite otherwise working perfectly.

After trying all sorts of things I bought the starter and sprayed it green before fitting. My first go at this and it took me 20 minutes (plus 10 minutes to spray green). It was really easy to swap, just a couple of bolts which needed a very long extension bar from front of engine.

The engine now starts so fast I don't quite have time to get my finger off the button.

 

[lustyd]

Oh, forgot to add that a good test for this is parallel batteries - if it starts better with more oomph it's probably this.

 

[Sealong]

Thanks for all your replies. Here are some of my own.

Just_sayin & Yotter: Thanks and I am aware of this and I shut the seacock during these prolonged periods of cranking the engine over.

Boater Sam: no smoke, tappets set a month ago, compression untested.

BobC: It may be low compression, but I would expect this to be accompanied by burning oil (due to excessive clearance between ring pack and cylinder bore). The engine uses very little oil.

Never Grumble: An interesting point, I did buy mine from that outfit. I will remove one and check.

Neeves: Relays are, as I mentioned fine. The exhaust elbow was replaced by me less than two years ago.

QBhoy: I replaced the engine oil at the end of last season and it still looks like honey.

Does anyone think that it could be a faulty feed (i.e. not injector) pump. I suspect this, because when cranking the engine is turned over at a relatively slow speed and a faulty pump may have trouble delivering fuel to the injector pump. However, once firing, the engine speed is much higher and a faulty pump would probably be able to deliver sufficient fuel.

 

[Sealong]

Oh, forgot to add that a good test for this is parallel batteries - if it starts better with more oomph it's probably this.

Lustyd, thanks. That too is a very good point and something easy to check out.

 

[Jokani]

BobC: It may be low compression, but I would expect this to be accompanied by burning oil (due to excessive clearance between ring pack and cylinder bore). The engine uses very little oil.

My 2020 had low compression, it didn't burn any fuel - In my case, new con rods were the answer. Not suggesting the same will be the case for you, just pointing out that I wouldn't eliminate low compression just because you are not burning oil.

 

[Sealong]

My 2020 had low compression, it didn't burn any fuel - In my case, new con rods were the answer. Not suggesting the same will be the case for you, just pointing out that I wouldn't eliminate low compression just because you are not burning oil.

I guess you mean oil and not fuel. That aside I do not see how new con rods would improve low compression. The con rod, CONnects the small end bearing on the piston to the big end bearing on the crank pin. Changing this would not affect the compression, other than by a very small amount from taking up excess clearances in the worn bearing surfaces. Loss of compression, would be caused by worn cylinder liners, worn piston rings, valve guides, and poor valve seats.

 

[peteK]

Rig up a gravity feed from a 5 litre fuel can bypassing the fuel pump and try that. If it then starts easily you will then know its a fuel supply problem and not a engine problem.

 

[Boater Sam]

If there is no white smoke with such prolonged cranking, it is not getting fuel from the injectors.

 

[cpedw]

. That aside I do not see how new con rods would improve low compression.

I don't think it's a common problem with Volvos but Yanmars have been known to bend their con rods, thus reducing compression.

 

[Tranona]

The con rod, CONnects the small end bearing on the piston to the big end bearing on the crank pin. Changing this would not affect the compression, other than by a very small amount from taking up excess clearances in the worn bearing surfaces. Loss of compression, would be caused by worn cylinder liners, worn piston rings, valve guides, and poor valve seats.

Bent con rods common cause of low compression, usually result of the engine ingesting water. Not heard of it on 2030s but common on GM series Yanmars. Bent tod means piston does not reach the top of its stroke and therefore the combustion space is larger. Test for Yanmar is to insert a piece of solder wire into the combustion chamber and measure the amount it compresses.

Not saying that is the problem with your engine butit could be poor compression from other causes. worth checking. I had a 2030 from new for 3500 hours and it was always an instant starter.

 

[Hoist]

might be worth you posting a video, can be so many things