Engine missfire

[curlass24]

Hi peeps,

 

We have a relatively new Lombardini engine in our narrow boat which has been running fine but recently started missfiring every now and then when it is on tick over.

 

Any thoughts on what this could be?

 

Thanks!

 

Malcolm

 

[WotEver]

Based on comments about these engines in another thread I don't believe you'll much like the responses you're going to receive.

 

As I understand matters Lombardini's stance is "Contact a Lombardini service centre".

 

See Tony B's post here: http://www.canalworld.net/forums/index.php?showtopic=88781&page=2

[Tony Brooks]

I would certainly make sure any engineer I got to look at it was very familiar with Lomabardinis and preferably a Lombardini trained agent.

 

I would make sure the external parts of the fuel system were clean/OK i case you have got water or muck in the fuel.

 

You could take the cam cover off and make sure there is sufficient valve clearance for each valve. Then assess how easy it would be to loosen each injector pipe in turn. If its easy without disturbing anything else then try it, one at a time when its misfiring and the one that makes no difference to engine running is the cylinder with the problem. I am not sure that I could advise you to take any offending injector out to get it tested because I have never been under the cover. It would be a case of look and see.

[curlass24]

thanks for the advice. is there a chance that this could be diesel bug related?

 

Our eberspacher which runs off the same tanks is also having issues.

 

If so how does one go about sorting this out?

 

Thanks

 

[Tony Brooks]

I would make sure I knew how to bleed both systems if they need it and change both fuel filters that are closest to the tank. Then drain the filters and in a spin on type cut them open too look inside.If you only find water the bottom of the tank needs draining by some means. If you find dark coloured jelly or slime it is probably bug. If you find a light coloured mousse or a waxy coating on the filter papers then it is probably an interaction between the fuel and a fuel additive, possibly an emulsifier type additive. (nothing 100% proven though).

 

In the latter case pump out whatever is sitting in the bottom of the tank and try a different additive of none at all. Change/clean all the filters and water traps.

 

In the case of bug you need to assess the severity. If only light use some of the concentrated Marine 16 biocide (small bottle) and be ready to do a few filter changes down the line. If its a bad case then either fuel polishing and biocide or even a more drastic treatment like cutting the tank open, high temperature steam cleaning, change all fuel pipes etc. and rebuild plus additive use. Be advised by the specialist you employ.

 

 

[Tony Brooks]

After some thought - I think the engine may well use cam operated unit injectors with mechanical fuel delivery control. If so I doubt there is anything under the cover the OP can do apart from checking there are no tight valve clearances .

 

Unit injectors are combined injector pump and injector in one unit so they only have a lowish pressure fuel supply running to them.

Edited December 7, 2016 by Tony Brooks

[bridge100]

Hi,

 

Which model Lombardini is it . If its a 1502 We had one in our previous boat.

It started misfiring, i sent the injectors to be serviced. I asked the then new agents fot the clearance setting (I ordered a manual which was on back order)for the roller rocker which operated the individual injectors. I was told it was the same as the valve clearances.

 

I fitted them and set the clearances as advised. WHITE SMOKE filled the cut from the exhaust.

I am reasonably experianced with engine so double checked everything. When the engine manual arrived and i read it i had been given incorrect information.

 

The setting up of the injectors is fairly complicated (the injectors have to stop "dribbling" at a preset position before tdc) and requires some special equipment which i still have. I also have the manual which also covers other engine types

 

The new agents are www.bryco.co.uk/Lombardini‎ who i have delt with with other engines and were very helpful.