Bleeding engines!!!

[driftus]

Hi, i wonder if any of you knowledgable boat people out there can shed some light on my innability to bleed the engine on my Arvor 20,The engine is a nanni 85 turbo it has a pre filter which i presume is to catch any water before it reaches the main fuel filter,i have bled the pre-filter untill there is clear diesel then bled the fuel filter untill the diesel also runs clear ,once the boat is out in the open water and i put the power on she seems ok for a while but then starts getting lumpy,the next step i've taken is to bleed the injectors whilst the engine is idling this seems to have done the trick but after three good bursts reaching speeds of 20 knots once again the engine loses its power as if being starved of fuel indicating to me that there is still air in the system,Help!!!

 

[hlb]

You've got an air leak.

 

[volvopaul]

Yes you have air leak, its probably on the filter head if it has a plasic round primer pump, the rubber splits and pulls air in, bypass it with a piece of hose and try it short term, if all ok then replace it, if its the 5 cylinder one I know my way round it well.

 

[orizaba]

i assume you have changed the filters etc,one other possibility is a restriction in the fuel system causing it to pull air in as it can't get enough fuel,maybe on your pickup pipe