Bleeding troubles

[Tiny Montgomery]

My engine, a perkins perama, cut out yesterday and when i checked i realised twas because id run out of diesel. Yes, stupid, i know. Ive put 40l in the tank, about a quarter of its capacity, but when trying to bleed the fuel line at the injector pump inlet im gettin no fuel spurtin out at all. Do i need to put more diese in the tank or am i looking at something more serious here? Please god, let it just be a matter of puttin more diesel in the tank!

[alan_fincher]

Sorry, but in any normal event, putting in 40 litres must mean there is now more than enough fuel in the tank.

 

So I would say that either you have not bled through to all the bleed points that may exist, or you have managed to draw stuff into the system that is not diesel, and block things up.

 

The latter is not that likely, I would have thought, as most take-offs are well above the bottom of the tank, and anything in the bottom of the tank should not get sucked in, even doing what you have done.

 

My guess is you just haven't bled it completely.

[Tiny Montgomery]

Thanks alan, i'll try again tomorrow. Is it normal then to just get puffs of air coming out? Im obviously no expert, but the last time i bled the fuel lines i was at least gettin some diesel coming out, albeit with lots of bubbles.

[alan_fincher]

Thanks alan, i'll try again tomorrow. Is it normal then to just get puffs of air coming out? Im obviously no expert, but the last time i bled the fuel lines i was at least gettin some diesel coming out, albeit with lots of bubbles.

I don't know this engine......

 

So have you broken the fuel supply on the inlet to the injector pump, and are you working a lift pump manually ?

 

Or is this a "self bleeding" engine ?

 

What exists between the lift pump and the injection pump ?

 

Would it be easy to break the output from the lift pump, to see if you have fuel getting through that far ?

 

Not a very common engine, (in narrow boat use), I think so don't be surprised if not many on here have one.

[Tiny Montgomery]

I am kind of baffled! I dont know where the lift pump is. Im basically doin what i saw the pennine cruisers man doin the last time this happened--loosening the two banjo bolts on the injection pump and pumping the little lever manually. When the pennine cruises man did this, there was fuel with air bubbles comin through. Now theres just air. Does that make any kind of sense?

 

And what im calling the injector pump turns out, i think, to be the feed pump. Sorry!

[alan_fincher]

Im basically doin what i saw the pennine cruisers man doin the last time this happened--loosening the two banjo bolts on the injection pump and pumping the little lever manually.

If you don't know where the lift pump is, what is the little lever you are talking about attached to, please ?

 

If it's the fuel input to the injection pump you are loosening and wanting fuel to come out of, why are there two ?

 

I'm confused as well.

 

If you are back with it tomorrow, it's probably worth taking and posting some pictures, so people can see which bits you are talking about.

[Tiny Montgomery]

I will do that. And it is the feed pump im talking about (i think) not the injection pump. There are two banjo bolts, one labelled IN and one OUT. This is the first thing the fuel lines come to after they leave the engine. If that doesnt help, which i doubt it will, i will try to be clearer tomorrow, with photographs. I shouldv posted this in the new to boating section, i now realise.

[alan_fincher]

I should posted this in the new to boating section, i now realise.

Not at all! You are in the right forum, not that most fuss much about that anyway.....

 

There will be loads on here who have no idea how to bleed their fuel system, I suspect.

 

Some engine types there is a very distinct knack to, and some examples of a particular engine type can be additionally quirky on top of that.

 

A local engineer says that on the BMC engines, (for example), some bleed though a doddle, but despite years of practice, others always take loads of faffing about.

 

Pictures will really help, as this is an engine few will be familiar with, (unless they know it from a "non-boaty" application.....)

[Tiny Montgomery]

Well, thanks for trying to help. Im pretty sure that its just somethin simple that im not doin right. Hopefully photos will make that thing clear!

[canaldrifter]

I'm guessing a bit, but it seems to me that you would have to bleed the fuel filter housing first if you ran the fuel dry.

 

You could do this by slackening the banjo connections on top of the filter housing, first on the 'in' side, then on the 'out' side, or there may be a bleed screw fitted. Once you've got diesel that far, tighten the cons and try bleeding at the injector connections.

 

The lever you are using is going to be on the lift pump. When bleeding, if you don't feel the pressure of fuel on the lever, then try slackening the connection to it from the tank, and see if fuel runs out. If it doesn't, you have a blockage twixt tank and lift pump (unlikely).

 

You may also have to prime the pump.

 

Good luck

 

Tone

[alan_fincher]

Well, thanks for trying to help. Im pretty sure that its just somethin simple that im not doin right. Hopefully photos will make that thing clear!

I've just realised I may be mixing Perkins Perama up with Perkins Prima.

 

I think this may be a more common engine than I may have wrongly been assuming.............

[Tiny Montgomery]

Ah, a glimmer of hope!

[nb Innisfree]

Don't know if it applies to boat engines but some road vehicles have self bleeding injector pumps i.e. the lift pump is incorporated into the injection pump, usually on Bosch pumps I think? In this case it involves cranking engine until it starts.

[PhilR]

Are you pushing the priming lever hard enough? - some require quite a lot of force to operate the diaphram. Follow the fuel pipes to the first filter after the lift pump and open the bleed screw on the top. If you are operating the lever correctly you should see fuel flowing from the bleed screw. If not there might be a blocked filter screen in the lift pump.

[Tony Brooks]

Are you pushing the priming lever hard enough? - some require quite a lot of force to operate the diaphram. Follow the fuel pipes to the first filter after the lift pump and open the bleed screw on the top. If you are operating the lever correctly you should see fuel flowing from the bleed screw. If not there might be a blocked filter screen in the lift pump.

 

 

Might also be that the engine has stopped in an unusual position so the camshaft is preventing you getting a complete stroke on the pump. Try turning the engine over one revolution and see if the slack on the lever decreases and the harder part of the stroke increases.

[Keeping Up]

Might also be that the engine has stopped in an unusual position so the camshaft is preventing you getting a complete stroke on the pump. Try turning the engine over one revolution and see if the slack on the lever decreases and the harder part of the stroke increases.

 

A good suggestion (as usual) from Tony.

 

My own engine (Perkins 104-19, aka MC42) is quite similar, and it often stops in just such a position that the lift pump doesn't work. It did exactly that last week after I had been fitting a new fuel filter, and it took two further attempts to get the engine to stop in the right place.

 

However I'm still puzzled by the description. My pump doesn't have banjo bolts nor does it say "in" and "out" but on the other had the fuel filter (which is after the pump) does have all those characteristics, and the first stage of bleeding is indeed to loosen those bolts and operate the lever under the pump until you get diesel out of them. In fact last week I completely removed the centre bolt form the "in" connector, so that I could better see what was happening. After the first attempts where the pump was in the wrong place, on the next attempt I could see the fuel squirting into the filter - but even after that it took quite a lot of pumping before the filter canister was full enough to cause diesel to come out of the banjo housing.

 

If this is indeed what you are describing, you will find that you need to pump until the "in" starts to dribble and you then close that one down, and then pump a fair bit more before the "out" starts to dribble. Beware, don't over-tighten them!

 

After that, the rest of the pipework will still be full of air but my engine will usually self-bleed from that point with a lot of churning on the starter.

[bottle]

All good advice but I would start at the tank take 'off' and follow the pipework, you may find a 'filter' agglomerator before the any pumps etc.

 

Work your way, from the tank, bleeding each filter, agglomerator on the way to the engine.

 

I do not know the engine but you may even end up bleeding the injectors.

 

ps, I bet you never run out of diesel again

[Tiny Montgomery]

Many thanks for all these suggestions, ill try my best to work through them. My problem is: if theres no fuel getting to the lift pump (which there isnt) then even after bleeding the engine wont start?? Thats why i wondered about puttin more diesel in, because the point where the fuel lines enter the engine bay seems very high compared to the level of diesel in the tank. Or should that not matter?

[Bimbly1]

Many thanks for all these suggestions, ill try my best to work through them. My problem is: if theres no fuel getting to the lift pump (which there isnt) then even after bleeding the engine wont start?? Thats why i wondered about puttin more diesel in, because the point where the fuel lines enter the engine bay seems very high compared to the level of diesel in the tank. Or should that not matter?

Think carefully about what you said in your last post.

If the engine cut out because the fuel level dropped below the level of the fuel line, the height of the fuel line in the tank is irrelevant. The engine stopped because it was starved of fuel. It did not use 40 or more litres in the last few moments it was running. Adding 40 litres of fuel will have raised the tank level significantly more than necessary to immerse the fuel line.

 

Keep on bleeding or consider blasting some air through the line into the tank if you think that there may be an obstruction.

Good luck.

 

Edited to correct spelling.

Edited April 2, 2011 by Bimbly1

[Tiny Montgomery]

Good point!

[MtB]

Many thanks for all these suggestions, ill try my best to work through them. My problem is: if theres no fuel getting to the lift pump (which there isnt) then even after bleeding the engine wont start?? Thats why i wondered about puttin more diesel in, because the point where the fuel lines enter the engine bay seems very high compared to the level of diesel in the tank. Or should that not matter?

 

 

I ran desperately low on diesel last year then ran out whist maneuvering onto the diesel pontoon, grrrr...

 

After refilling then spending three hours trying to bleed the air out of the system just as you seem to have, and failing too, I gave up and employed the boatyard diesel mechanic to do it for me.

 

After asking what I'd done to bleed it, he elected not to even try bleeding it the conventional way. Instead he got me to turn the engine over while he cautiously sprayed easystart into the inlet. After running it for about 10 seconds on easystart it began to fire erratically and after couple of further goes, it ran steadily on one cylinder, then two, then three.

 

Took about ten minutes in all, for which they agree to waive their minimum one hour labour charge and billed me for half an hour. Very fair I thought. It was Napton Narrowboats by the way.

 

(Sorry, veered off topic slightly at the end there:-) )

 

Mike

[FORTUNATA]

Undo both vents on your filter and fix a bike pump to the inlet vent. It needs to be tight on. Draw the bike pump handle and fuel should fill the filter and gush out of the outlet vent far far faster than messing about with a lift pump. If fuel is not drawn into the filter rapidly by the suction then you need to check the main fuel supply line to the filter. Check the hoses both sides and connections. I've found tears before that weren't noticed as you need to inspect the hoses both sides.

 

My engine, a perkins perama, cut out yesterday and when i checked i realised twas because id run out of diesel. Yes, stupid, i know. Ive put 40l in the tank, about a quarter of its capacity, but when trying to bleed the fuel line at the injector pump inlet im gettin no fuel spurtin out at all. Do i need to put more diese in the tank or am i looking at something more serious here? Please god, let it just be a matter of puttin more diesel in the tank!

[Tiny Montgomery]

Bleeding hasnt bleeding worked.

 

Ive disconnected pipes just before the shutoff valve and theres no fuel running through. So if theres a blockage it seems its before shutoff valve, even though theres only about 15cm of pipe before that. This has stumped me. Looks like its time to call in the expensive professionals.

[Justme]

Blow some air back up the tank line?

[Chris Pink]

Bleeding hasnt bleeding worked.

 

Ive disconnected pipes just before the shutoff valve and theres no fuel running through. So if theres a blockage it seems its before shutoff valve, even though theres only about 15cm of pipe before that. This has stumped me. Looks like its time to call in the expensive professionals.

 

Sounds like you're nearly there, when you say 'before' do you mean toward the tank? ie with the valve open no diesel comes out of the tap?