Fischer Panda 4.5 kva ac Genset

[Simister]

Hi all,

I have a Fischer Panda 4.5 kva genset with a single cylinder Ferryman engine and only 250 engine hours. I have a starting problem that has developed.

This problem only occurs when I have left the boat unattended for about a month. When I return to the boat it takes about 20 cranks of the engine to start. When it fires up it works perfectly. From then on it starts first time every time for weeks on end. When I leave the boat again for a month I have the same problem ie: slow to start.

I have checked the fuel pump, fuel solenoid and bled the fuel system with no change. Somebody told me it could be low on compression, but I thought if that was the case it would be difficult to start every time.

Thanks John

[djmarchand]

John:

Your problem is most likely an air leak in the fuel supply line. Check every connection from the fuel pick up to the fuel pump. Air is slowly leaking in to the system and it takes cranking a while to push (well, pull actually) it through.

David

[Simister]

Thanks for the advice. I will check the fuel lines.

[svHyLyte]

Originally Posted by djmarchand

John:

Your problem is most likely an air leak in the fuel supply line. Check every connection from the fuel pick up to the fuel pump. Air is slowly leaking in to the system and it takes cranking a while to push (well, pull actually) it through.

David

We have the FP 4.2KW FW cooled generator and find the same thing. A few weeks of non-use and she's a bit slow to start. Otherwise the motor starts within 2-3 seconds. I suspect it may be due to the oil pressure switch that prevents the fuel pump from activating until adaquate pressure has developed in the oil galleries. After some while these completely drain out and oil collects in the sump and it takes a while for the cranking engine--at relatively low rpms--to get the system pressurized enough to activate the fuel pump. Just my guess, of course, but it sounds plusible and given the high rpms of these motors, one wouldn't want them turning over without adaquate oil pressure to "float" the bearings, no? (OTOH remember that I am/was a structural engineer not a mechanical/electrical guy so my knowledge of such affairs is on the thin side!)

FWIW...

[Sailmonkey]

roller bearings...........no need to float.
But this is not an uncommon problem with these generators. Run them when you're near them, and expect a hard start when you're not with them for a while.


I retract......it could be, as there are plain bearings on everything except the flywheel end of the crank.

[Simister]

I have checked the fuel lines and they are all secure. I don't suspect air is getting into the system. I had already suspected air in the lines so the last time I came up to the boat I bled the fuel system first before starting - same problem (20 cranks to start).

I have a mate with exactly the same genset and is also experiencing this problem so I think Sailmonkey may have a point and this is part of the issue with these small engines.

[s/v Jedi]

Originally Posted by svHyLyte

I suspect it may be due to the oil pressure switch that prevents the fuel pump from activating until adaquate pressure has developed in the oil galleries

+1 I'm with HyLyte

ciao!
Nick.

[Simister]

So what are we saying here?

That the pressure will hold in the oil galleries for a few days but after a few weeks needs to be re pressurized by extensive cranking?

If this is the case, (and it certainly makes sense) is this normal for small diesel engines or can it be fixed? The engine only has 250 hours but it is 10 years old.

[FlyingCloud1937]

Originally Posted by Simister

So what are we saying here?

That the pressure will hold in the oil galleries for a few days but after a few weeks needs to be re pressurized by extensive cranking?

If this is the case, (and it certainly makes sense) is this normal for small diesel engines or can it be fixed? The engine only has 250 hours but it is 10 years old.

Makes no sense at all, first the oil galleries won't hold pressure for more then a couple of seconds after the oil pump shuts down ie: engine stops.

Oil in the cylinders will create grater compression at the rings when wet, less then when dry after setting for a week or 2. A sign of low compression or improper break-in, or lightly loaded causing cylinder glazing, which results in low compression.

Second, most generators use a bypass alarm circuit, during the the start crank.

So that leaves either fuel pressure, bc of air in the system, low turnover during cranking or low compression.

Low compression can be caused by improper brake-in when the engine was new, and will only gradually get to the point that it shows up after warm-up.

Trouble shoot as follows:

Make sure the battery has enough cold cranking amps to turn the engine over at cold start-up.

Trouble shoot as follows: pressure test the fuel systems and make sure it holds pressure.

Do a compression check on the engine cylinders when cold, and then after warm. A differential will be suspect.

Lloyd

[Simister]

Low compression due to cylinder glazing could be a possibility as I have been guilty of running the engine lightly loaded.

I have plenty of cranking amps and the engine turns over very quickly.

What is the best way of dealing with the removal of cylinder glazing?

I will pressure test the fuel system and do a compression test.

[FlyingCloud1937]

Originally Posted by Simister

Low compression due to cylinder glazing could be a possibility as I have been guilty of running the engine lightly loaded.

I have plenty of cranking amps and the engine turns over very quickly.

What is the best way of dealing with the removal of cylinder glazing?

I will pressure test the fuel system and do a compression test.

What is the best way of dealing with the removal of cylinder glazing?

Depending on the state of glazing run the engine at at 80% of rated load when ever it's running. After it's glazed, your only hope is to run it at max capacity for 20% run cycle, ie: 2hr run=1.6 hrs at 80%, and .4 hrs at 100%, then give it a 50% load cool down cycle for a couple of minutes.

If a diesel engine isn't broken in properly it will start to lose compression, and begin to slober, once this happens, removing the pistons and honing the cylinders, with new rings is the likely only fix...and that if things remain in tolerance.

As critical as break-in is to a diesel engine, so is loading it properly, and lightly loading is only behind pour oil, and cooling...otherwise a diesel engine will give thousands of hrs of good service.

Lloyd

[Simister]

Thanks Lloyd for your advice.

How long would you think it would take to remove the glazing at the load rates you suggested?

[FlyingCloud1937]

Originally Posted by Simister

Thanks Lloyd for your advice.

How long would you think it would take to remove the glazing at the load rates you suggested?

I don't have a magic hat, so it would only be a shot in the dark. How many hrs are on the engine? did you follow the break-in procedure listed in the owners manual? how much of it's life has it run light loaded?

If the prescribed duty is going to work it should improve with in about 20-30 hrs run time...if it doesn't it wont ever.

Make sure the fuel pressure system isn't leaking down first step, if after that and a vigorous run cycle doesn't stop it. You have 2 choice ...live with it, or try the cylinder hone, and ring job.

The compression test will give you the answers if the fuel pressure test holds.

Lloyd

[Simister]

It all makes good sense.

Glazing seems to be the most likely problem. The engine has 250 hours and I would say it has run at around 50% load for most of its life.

It is 4.5 kva which should be about 20 amps at 240 volts. I generally run the genset drawing around 10 amps most of the time.

Thanks again Lloyd for your help.

[Tellie]

Is there any black smoke at start up after it's sat for awhile?