Perkins 4.108 diesel engine not starting

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karlosmartines

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Hey!

So I bought my first boat, a Finnsailer 29 '74 with the original '74 Perkins 4.108 diesel engine, last august and sailed it to the city where I'm living. After getting it to port I had one trip and after that, early-mid september, the boat has been laying still on the water. Before going home for christmas I tried starting the motor to do my first oilchange and winter maintenance, but the motor didn't start and I haven't gotten it to start since.

I do not have any prior knowledge with engines so I feel I need some consultancy. The manual has a trouble shooting guide, but since the engine went perfectly for the whole voyage, 1.5-2 weeks, I'm thinking that it isn't a huge problem. Thinking maybe I want to bleed the fuel system before starting the troubleshooting or try something else.

When sailing last summer there was white smoke coming out of the induction manifold when glowing, but now it ain't. Also the starting engine has not been going as fast/tight every time, but other times with no problem. Do any of you have tips for things I should do before I start the troubleshooting process? Good tutorials, guides or other tips for how to beed the engine?

I am very grateful for all the help and suggestions I get!
Best
Karl
 
Hi Karl. Are the batteries fully charged? That engine needs a good swing over to get it going. Also might need bleeding the fuel system, but if it was going fine before then there can't be much wrong with it. Good luck. Also don't forget it has a glow plug which need about 5 seconds before you start it.w
 
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chrishelen said:
Hi Karl. Are the batteries fully charged? That engine needs a good swing over to get it going. Also might need bleeding the fuel system, but if it was going fine before then there can't be much wrong with it. Good luck. Also don't forget it has glow plugs which need about 5 seconds before you start it.
Click to expand...
The 4108 has a pre heat in the inlet manifold no glo plugs
 
Can we assume that the starter motor is trying its best? If not, as Chrishelen says, look to your batteries.

But for most older diesel engines after a period of layup, the usual problem is to get the fuel flowing back through, and clearing out any condensation that has formed in the cylinders. This is essentially about the fuel lift pump, and probably of re-establishing the syphon connection to the fuel tank. You are quite right to think that bleeding the engine is the likely solution: it sounds formidable if you haven't done it before, but really, with a 4-108 is quite easy if you follow the workshop manual. (Download a copy if you don't have one.) Otherwise, get a mechanic to show you, it shouldn't cost an arm and a leg, and once you know how, then you know how.

Of course there are other possibilities, such as the injectors being clogged, but worry about that later.

My experience with 4-108 engines is that although they are fitted with pre-heaters, unlike some other diesels it is rare that they really need these to get going.
 
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Old Harry said:
The 4108 has a pre heat in the inlet manifold no glo plugs
Click to expand...
He said no white smoking which is what you see when you use the manifold heater as it vapes the diesel in it. I helped a chap a few months ago, you cant get at the top bleed screw on the inj pump because of the heat exchanger so if he has lost prime then he needs to crack the injector pipes to bleed it.
 
Sounds like a problem with the thermostart (not thermostat!!!) That is the thing in the inlet manifold. It needs a supply of diesel to work. Does it have it's own reservoir or is it fed directly from the fuel filter housing. If the former then the reservoir may be empty.
 
I sailed a boat for a few years with a 4108 and I now have the 4236. Sounds exactly like a battery in a state of low charge. My current engine is lumpy (a good description) when battery is low. There should be a healthy turn of speed when on the starter. Before you do anything else, get the battery fully charged.
 
Thanks everyone!

Then I will definetely try to bleed the system during the weekend!
I've tried with the battery fully charged, but the starter have been both lumpy and at a healthy turn of speed then as well. The previous owner had bought a new starter which I got with the boat, so I can change that out also if it still lumps. Is that something I will need a mechanic for or is that something I can do my self as well?

Thanks again
Karl
 
If the batteries are good, but the starter is not turning the engine as fast as it should, look for corroded terminals between the battery and starter, particularly the negative return circuit. A corroded terminal will get warm or in a really bad case smoking hot. Whichever it will slow the starter enough to prevent the engine from firing. Starter speed is critical. A good clean of all the terminals is often needed in a boat that has stood for 6 months+.
 
Karlos
You don't say where you are. Is it a lot colder than when you last started the engine? If the Thermostart is not operating (no white smoke, smelling of diesel, coming out of the inlet) then the combination might be the reason, along with low cranking speed.

I quick test would be to use easy-start(ether spray), or even WD-40, sprayed into the inlet while cranking.

Ah! Just re-read your post. So the gap was Sept to December, so cold when you last tried?

I got an old and tired VP MD11 to go in the cold by using an electric heat gun to warm the aircleaners and inlet.
 
AndrewB said:
Can we assume that the starter motor is trying its best? If not, as Chrishelen says, look to your batteries.

But for most older diesel engines after a period of layup, the usual problem is to get the fuel flowing back through, and clearing out any condensation that has formed in the cylinders. This is essentially about the fuel lift pump, and probably of re-establishing the syphon connection to the fuel tank. You are quite right to think that bleeding the engine is the likely solution: it sounds formidable if you haven't done it before, but really, with a 4-108 is quite easy if you follow the workshop manual. (Download a copy if you don't have one.) Otherwise, get a mechanic to show you, it shouldn't cost an arm and a leg, and once you know how, then you know how.

Of course there are other possibilities, such as the injectors being clogged, but worry about that later.

My experience with 4-108 engines is that although they are fitted with pre-heaters, unlike some other diesels it is rare that they really need these to get going.
Click to expand...

UPDATE:

I always make sure to pre heat before cranking.
None of the terminals from battery to starter motor is corroded.
To me it looks like fuel is directly fed from filter housing.

The starter motor is definetely not trying its best. The starter battery is not fully charged and I'm charging it again now, but connected with the service battery this is the performance (see video):
https://www.youtube.com/watch?v=542TUOsTstI&feature=share

As mentioned I got a new starter motor with the boat when I bought it and this is what the old one looks like the picture56582267_359404441335936_1910654783316819968_n.jpg

Assuming the battery is fine: is this (the lumpy starter) a definitive sign that the starter motor should be changed? If not what could it be?
 
It sounds like low power getting to the starter motor, which is probably the because the batteries are low. The quicker turn over at the start of the video followed immediately by the lumpy turnover suggest that the batteries are quickly drained as the engine is initially forced to turn. The turn over speed at the start appears far to low to me, again a symptom of low batteries.

I would also inspect the starter motor brushes and clean out any dust from the brushes which has smeared over the commutator ring, but only after charging the batteries and trying again.
 
That’s definitely not turning over fast enough. Batteries and connections are where I would start. Also make sure that when using the thermostart, you turn the key just beyond the first click. You know that it is on because you will see the current draw on your ammeter.
 
Hello:

I had a 4108, that ran under testing, then just after launch wouldn't start, I needed a new starter battery to get the cranking up to speed.
Also, when using the preheater, keep it on for approx 15 secs (20 in winter), to ensure it's preheated properly.
After I moored up I went home, three weeks later the engine wouldn't start, even though nothing had changed in the meantime.
It turned out the fuel (which had come with the boat and had been standing for goodness knows how long) had diesel bug that had 'blossomed' since I moored up and it had clogged all the fuel filters with a slime like jelly. I changed the primary for one with a glass bowl so I could keep an eye on it, and changed the secondary with the same as I took off, and treated the fuel with diesel bug treatment from ebay (approx £15), after that it started first time for 5 years.

I just made sure I treated the fuel at every fill up, just to make sure the bug didn't come back.
 
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