Bukh DV20

[virtualgardener]

I have a 20 year old Bukh DV20 in my Sadler 32 which has proved very reliable during the fifteen years that I have owned the boat. Recently the engine has developed the habit of stopping when I throttle back to idle speed or try to put the engine in reverse. This causes real problems when trying to manouvre in a confined space such as a lock or in coming alongside a pontoon. I was advised that the cause of my problem is fuel-related and an engineer has replaced the lift pump, fuel pipes and fuel pump, serviced the injectors, cleaned out the tankand increased the revs when idling. However the problem persists. Can anyone suggest a solution or should I just give up and buy a new engine? /forums/images/graemlins/confused.gif

 

[Rick]

Sounds like you need a new engineer! Find a knowledgable one, and employ him to solve the problem, not replace parts.

 

[Gunfleet]

I've had a similar experience with a Yanmar. Suggestions... has there been a compression test? Is the exhaust clear? Does the governer stick?

 

[oldharry]

Similar thing happened to a container ship in southampton recently: demolished a loading ramp and various other dockside bits.... nasty!

Doesn't sound like a fuel fault as the engineer has spent a lot of your money replacing bits that were not broken. In any case I would not have even been looking at half the bits he has done for this kind of fault.

Presumably all the ancillary fuel bits have been checked? Particularly the filters, and fuel feed pipe connectors, and not forgetting the little filter in top of the fuel lift pump.

If you have the standard rbber 'diesel hose' exhaust, check the internal liner for damage near the manifold end. It should be smooth. If it is rough and wrinkled, then the chances are you have a flap of rubber which is allowing exhaust to pass on open throttel, but acting as a valve when you slow down, blocking the exhaust and stopping the engine. As soon as the engine stops, it springs back into place, and allows the engine to re-start.

This is caused by an overheat situation where the water supply to the exhaust has been lost while running, and the pipe has been scorched.

It was a very common problem on the old Vire petrol engines - which was where I first came across it. Otherwise, ask a Bukh main agent, they are very helpful with free advice.

 

[steve28]

Try increasing the idle speed, this was the cause of mine doing this.

steve

 

[chriscallender]

Mine (of similar vintage) occasionally did that. It was caused by an air leak into the fuel hoses.

So I wonder that the engineer might still have been along the right lines but these kind of things are pretty hard to find.

What I would try doing is replacing the return pipe from the engine to the fuel tank with some clear hose temporarily and then see if there are any air bubbles in the fuel returned back from the engine when the throttle is open and the engine under load. On mine, the bubbles were really easy to see.

If there are, then its (just!) a case of finding where the air is getting in. As well as all the hoses, connectors etc it can be getting into the pickup pipe inside the fuel tank.

Good luck

Chris

 

[30boat]

I had that happen to my diesel car some time ago and it turned out to be the alternator that stalled the engine because the battery wasn't holding it's charge anymore.When I desacelerated the alternator load then proved to be too much and the engined stalled.However I doubt that's the case but one never knows...

 

[GeoffW]

Have you cleaned/replaced the fuel filter on the engine (screw on) and the lift pump filters. A dirty lift pump filter can cause 'spluttering' which may lead to the engine stopping.

 

[virtualgardener]

Thanks everyone. i have replaced all fuel filters and have had a new exhaust elbow and flexible hose to the water trap.

 

[SimonJ]

I recommend you discuss your symptoms with BUKH HQ in Poole. They are incredibly helpful & knowledgeable.
They will no doubt tell you that if still fitted the filter on the fuel lift pump should be removed as it is redundant!
Hopefully you do not have any water in engine from the achillees heel problem of failure of water pump seals. Dirty or contaminated oil will affect injector fuel pump.
Engine idle should be checked against a tacho.
Is the non return valve in valve gear area (connected to air inlet) clean and operational?
PBO did a good article on BUKH a few years ago and reprint is available.
Good luck.
Fuel cleanliness, tank especially, is critical.

 

[H4B]

Have had exactly the same problem. Call Bukh Uk at Poole they will explain what the problem is and how to fix it. The problem is with the governer in the injection pump (sticking jaws on the rack ), nothing to do with fuel filters or compression etc. In the mean time always try to reduce revs slowly and in gradual steps back to idle especially after you have been running at high revs for some time with a warm engine. Do not buy a new engine if it starts Ok and does not smoke then the engine is fine and tell the engineer that did all the work for you that he should have called Bukh and asked them before wasting your money. This is not terminal ! Good luck