Fischer-Panda 6KW dies under load

[marcog]

Dear All,
we have a Fischer-Panda 6KW diesel generator on our boat which used to work just fine.
Recently it started to misbehave. I starts and runs fine with no load, but dies immediately when put under load. It does not even try to increase revs as it should, it just stops.
The primary fuel pump seems to be working properly, even though I didn't check the flow. Might those be symptoms of fuel starvation?
Plus I would expect an attempt by the genset to increase its revs when load is applied, while it doesn't do it and simply dies. Maybe the actuator to the injection pump is jammed?
When it stops, the panel shows engine failure and oil pressure failure. I checked the oil and it seems to be fine.
Anyone has experience with these symptoms on similar units and can recommend some troubleshooting steps? The manual doesn't mention this case.
Thank you very much in advance!
Fair winds and following seas,
Marco.
S/Y Kismet

[sigmasailor]

I would start with the simple things: did you check your fuel filters?

[marcog]

Thank you sigmasailor, will surely do. Checking the whole fuel line up to the injection pump is definitely on top of my list. Unfortunately I am not close to our boat now, so I am collecting few hints on where to start next time I am there.
I was thinking though that if it was a fuel problem, I guess the engine would try to increase it revs and then die because not enough fuel gets to the injection pump, but in this case it runs just fine until load is applied, then shuts off. It seems to me that the act of applying load trips some internal protection because of another problem (to be identified) and thus the genset shuts off... Did you have any similar experience?

[sigmasailor]

No hands on experience with your type of engine; fuel problems are not uncommon. The alarm you got could be explained by fuel starvation though. It didn't stop normally so the system could see oil pressure and general engine failure as faults while these are the result of a simple 'stall'.

Hard to say from a distance; hope you get more useful tips.

[HappyMdRSailor]

Marco,

No true experience with a Panda, but :
A) I agree with the fuel delivery possibility...

B) I lean more towards your intuition of something "Not" increasing the throttle to load... Whether that be some electro-mechanical fault for the injection pump, or some "mystery" electrical load" sensor shutting it down... because the engine isn't increasing, or the load is too high for the generated current under idle.... This smells like the chicken and the egg thing to me...

Do you have a manual?

[Dockhead]

If the panel shows oil pressure failure, thats a clue. A bad sender could be activating the low oil pressure cutout. I doubt it would show this fault for no reason.

[HappyMdRSailor]

Originally Posted by Dockhead

If the panel shows oil pressure failure, thats a clue. A bad sender could be activating the low oil pressure cutout. I doubt it would show this fault for no reason.

DH...

Why does it run fine with no load then? Wouldn't oil fault show on stall???
Genuine Questions... Not Debate starters!!

[Capt.Alex]

Does it seem to struggle at all before it dies? Or, does it shut down instantly? It sounds like it is the latter, which would more likely be a sensor shutting it down rather than it stalling from fuel starvation.

[HappyMdRSailor]

Originally Posted by Capt.Alex

Does it seem to struggle at all before it dies? Or, does it shut down instantly? It sounds like it is the latter, which would more likely be a sensor shutting it down rather than it stalling from fuel starvation.

Alex.. That's what I'm reading from it....

(back later today for progress)

[westwinds]

I am in agreement with a fuel problem, probably contamination of diesel with water that has messed up the governor on the fuel injection pump. I actually do not know what kind of diesel injection system this engine has so just a wild guess.

[Moonos]

While I'm no expert on diesel engines, from my experience the oil pressure failure warning light is simply due to the engine stopping and subsequently loosing oil pressure while the ignition is still on. This would also happen with running out of fuel or any other reason causing the engine to stop with the ignition still on.

Perhaps look at the circuit that increases revs due to an increase in electrical load?

Can you manually increase the revs of the engine, idle adjustment or similar? That should give clues.

[ontherocks83]

Originally Posted by Moonos

While I'm no expert on diesel engines, from my experience the oil pressure failure warning light is simply due to the engine stopping and subsequently loosing oil pressure while the ignition is still on. This would also happen with running out of fuel or any other reason causing the engine to stop with the ignition still on.

This was my thought. Just like if you stall a standard car all the warning lights come on but don't mean anything.

When you apply a load does it die instantly or peter out?

Can you apply even a small load or does anything kill it?

After it dies does it start right up or struggle?

What has the maintenance history on it been?

First thing is we really need to determine if this is a fuel restriction issue (dirty filter), a sensor issue (electronic), or a fuel regulation issue (governor/pump).

any and all specifics will be helpful

[marcog]

Dear All,
I appreciate very much all your hints and recommendations!

Few answers to some of the questions above:
1) Water in the diesel? I would tend to exclude that. The diesel comes from the same tank as for the boat engine (Volvo Penta) and the engine has 2 Racor filters. I didn't see any water in them and the engine runs smoothly.
2) The generator starts properly and runs fine on idle. Then it dies immediately (no shuttering or anything) as soon as I apply a load to it (I tried with the water heater and/or the battery charger). It is like when you switch it off from the panel with the OFF button, but in this case it is an unwanted stop.
3) Waiting few minutes after it has died, taking the loads off, then restarting it is no problem. It starts as before, then dies again once load is applied.
4) I didn't hear any rev increase as the load is applied. Dies immediately. Either has no time to throttle up because it switches off or cannot throttle up so it switches off.
5) I looked through the manual and it doesn't mention this case. I read however that the spindle on the actuator requires maintenance and lubrication as it may jam.
6) As far as I know the generator has been maintained properly by the previous owners and it ran just fine this summer while cruising. It just reached 1000 hours.

Anyone knows if on the Fischer-Panda there could be some kind of sensor on the actuator that drives the throttle on the injection pump, so that if it doesn't turn as expected to increase the revs once under load it will shut down the whole system?

Unfortunately, as I wrote above, I am far from the boat at the moment but plan to do some troubleshooting, follow your advise, as soon as I will be back onboard.

Many thanks again to you all!

Marco.

[nhschneider]

I have seen exhaust restrictions cause similar problems. Sometimes the inner wall of an exhaust hose can separate and cause enough restriction that the engine will idle but dies when the exhaust gas velocity increases as it does when a load is applied. Just something to keep in mind.

Fair winds and calm seas.

[sailinglegend]

Originally Posted by marcog

5) I looked through the manual and it doesn't mention this case. I read however that the spindle on the actuator requires maintenance and lubrication as it may jam.....

We have a 4Kw FP and have had this problem with ALL the faults listed below.

First check the actuator that can get stuck and should be oiled once a month. To do this you can disengage the starter motor and then try to start the engine. It will go through its start-up procedure of switching on the fuel pump and moving the actuator arm but off course the engine will not turn. If the actuator moves a significant way along the spiral that sounds OK. If it doesn't move the arm is stuck or the wires could be loose. In this "test" mode you can also check the fuel return back to the diesel tank. Disconnect that and feed the pipe into a jar and check no air bubbles up in the jar. IF it runs continually at idle then fuel is getting through, buy if no fuel comes at all the pump is faulty or the wire loose, or the pump relay faulty. You should have at least three replacement relays, a standard car unit for 10$, or an FP price about 40$.

To disengage the starter motor there is a small push-fit wire on the solenoid on top of the starter motor. This is between the large RED cable and the body of the motor. This should be easy to find.

If this doesn't find the fault then the fuel solenoid could be partly opening or the exhaust elbow is blocked.