Hi, I hope that someone may be able to give me some advice on my Lister Petter LPWS2 (build 42) which has developed a fault in my narrowboat. When under heavy load it starts to slow down and there is a sort of slapping noise before it finally stalls. It will then not start for about a minute and when it finally starts there is a cloud of blueish smoke from the exhaust followed by brown smoke. It runs fine at low revs under load and high revs in idling.

Thinking it was fuel related I have checked all of the fuel lines for air and dirt at the primary filter, the lift pump and the return feed to the tank, I have also checked the primary pump and the fuel was clean.
I have changed;
1. The fuel filter,
2. Oil filter,
3. The oil (with 10w/40)
4. The injectors

The fault still exists and I am running out of ideas. The only areas that I think it could still be are the two injector pumps or a problem with the Governor, but will have to take the engine out to reach these, which I don't want to do unless I have to.

If anyone has any ideas or experience of this fault and the rectification I would be very grateful.

Thanks