Liebherr Engine Problems

[Jason-020]

Hi. I have a Liebherr A902 wheeled excavator at the moment. The engine seized (D904T model engine)
I have since replaced the engine with a very very similar engine D924T-E model. It just will not start no matter what I do. Am I missing something electrically? I have had the injectors and injector pump refurbished, engine timed to perfection, it is turning over fast and injecting diesel out of the feed pipes into the injectors themselves. But still will not start no matter what i do... I'm at a loose end. Am I missing something?

Thanks a lot in advance, Jason

www.pattersonplantsales.co.uk

 

[Jim D]

Wow... First thing, do you have any smoke from the exhaust pipe? White?

If not, and if the timing is correct, and the pump is good and getting fuel, make sure that the lines to the injectors are completely blead of air. I don't know the loader, but I'm thinking of a Deutz 914 engine. I've seen sone engines where it took for ever to fill the fuel injector lines, that is, bleed them. Had the lines loosened at the injectors and cranked the engine many, many times, and had fountains of fuel squirting at the injectors, and it took for ever for the engine to start.

The volume of fuel injected is very small, and the break-open pressure of the injectors is high, so it only takes a small bubble of air in the injector line to prevent the injector from opening.

 

[Jason-020]

Wow... First thing, do you have any smoke from the exhaust pipe? White?

If not, and if the timing is correct, and the pump is good and getting fuel, make sure that the lines to the injectors are completely blead of air. I don't know the loader, but I'm thinking of a Deutz 914 engine. I've seen sone engines where it took for ever to fill the fuel injector lines, that is, bleed them. Had the lines loosened at the injectors and cranked the engine many, many times, and had fountains of fuel squirting at the injectors, and it took for ever for the engine to start.

The volume of fuel injected is very small, and the break-open pressure of the injectors is high, so it only takes a small bubble of air in the injector line to prevent the injector from opening.

Thanks Jim! I'm getting no smoke at all really when I turn the engine over... You recon turn the engine over rapidly for about 30 seconds with the feed pipes open? The diesel is coming at a fast rate! I just thought there's maybe something electrical in the engine itself, like a flap not opening or something along those lines, I've never seen anything like this before
Thankyou, Jason

 

[Nige]

As a quick check to see whether the problem is lack of fuel, try squirting a small dose of aerosol starting fluid on to the outside of the air filter primary element while cranking the starter and observe whether or not the engine pops and bangs like it's trying to pick up..?
If it does then your problem is definitely fuel-related somewhow as in not getting any. If it still plays dead then I would suspect that something is wrong with the valve timing.

 

[aongheas.macask]

Check that injectors are installed properly, it's possible to fit them 180 degrees out, the leak off pipe is normally on the left hand side of injector looking from inj pump side. I have seen this a few times but the engine usually starts but smokes badly. Are you confident that the pump and injectors are good ? (Overhauled by Bosch agent).

 

[Jason-020]

Check that injectors are installed properly, it's possible to fit them 180 degrees out, the leak off pipe is normally on the left hand side of injector looking from inj pump side. I have seen this a few times but the engine usually starts but smokes badly. Are you confident that the pump and injectors are good ? (Overhauled by Bosch agent).

I have been trying EasyStart fluid into the intake pipe and it does fire and run on the fluid only. Getting no diesel smoke at all even though the injectors are getting more than enough running to them... Injectors and Injector Pump had a full refurb at £1000 from a local Bosch registered refurbishment specialist.. Something just isn't adding up guys...

 

[Birken Vogt]

No diesel "smoke" (atomized fuel) might mean that something is causing the injection pump not to deliver enough pressure to open the injectors even if fuel does show when they are opened to atmosphere.

Since it is a hassle I would exhaust all other avenues and then remove an injector or two along with its associated pipe and if possible reinstall things backwards with the injector out of the engine so that you can see the spray pattern or lack thereof when cranking. Of course the high pressure spray is dangerous to skin so stay clear.

 

[Nige]

I have been trying EasyStart fluid into the intake pipe and it does fire and run on the fluid only.

If that's the case you have no fuel to the injectors. If you had fuel - even if the injection timing itself was wrong - you would be getting some smoke out of the chimney.

 

[lantraxco]

You would think so, but what if the injection pump is timed 180 out? Injecting fuel during the exhaust stroke, I would think you would see or smell it out the exhaust but? Just throwing it out there.

 

[Nige]

Even if it was 180 degrees out you would be smelling unburnt diesel somewhere, either up the chimney or in the air filters - IMHO.

 

[aongheas.macask]

No diesel "smoke" (atomized fuel) might mean that something is causing the injection pump not to deliver enough pressure to open the injectors even if fuel does show when they are opened to atmosphere.

Since it is a hassle I would exhaust all other avenues and then remove an injector or two along with its associated pipe and if possible reinstall things backwards with the injector out of the engine so that you can see the spray pattern or lack thereof when cranking. Of course the high pressure spray is dangerous to skin so stay clear.

I agree, if you do not get a good spray pattern then it points to the injector pump not putting enough pressure out atomise the injectors, I know you have had the pump overhauled but this is my experience,I'm not sure what pump is on this engine but I have seen the earlier engine inj pump being low on pressure , if you look at the injection pump where the pipes come out of the delivery valves in the centre there should be a three sided plug, these were prone to coming loose and the pressure would drop considerably, if this is the pump on your engine then try to tighten this plug, don't know the torque setting but you can try by feel anyway.

 

[Jason-020]

Even if it was 180 degrees out you would be smelling unburnt diesel somewhere, either up the chimney or in the air filters - IMHO.

I think removing the injectors and trying to start the engine with the bottom of them exposed to see if they are squirting diesel would be worth a try as a guy said above... It couldn't do any harm surely could it?

 

[Nige]

I think removing the injectors and trying to start the engine with the bottom of them exposed to see if they are squirting diesel would be worth a try as a guy said above... It couldn't do any harm surely could it?

It certainly wouldn't. Based on your experience up to now the engine isn't likely to start anyway.
Pull only one injector and have it coupled up to the HP fuel line in such a way that the spray from the injector is directed away from you when you crank the starter. The pressure of the fuel coming out of an injector nozzle will drive fuel clear through skin and flesh - BE CAREFUL ....!!

 

[aongheas.macask]

Interested in what you found, hope you got it running

 

[aongheas.macask]

Interested in what you found, hope you got it running

Still interested in what you found

 

[thepumpguysc]

Yes, its very possible to have fuel AT the injector line and NOT have enough pressure to open the injector.
Pull 1 injector and hook it back up to the line.. DO NOT crimp the line.. a slight bend is OK.. even if its laying on its side.. it doesn't have to be standing up straight..
Just enough to see if fuel is squirting out of it..
AND as the others have said.. STAY CLEAR OF THE SPRAY..
Good luck..

 

[Nige]

The OP hasn't been back here since March 24th so I guess this is another of those issues where we're never going to find out what happened .....

 

[ssv115511]

Liebherr Lidos All manuals download for free http://adf.ly/1ZjGrY

 

[ssv115511]

Literature Liebherr engine http://kkatalog.blogspot.ru/p/libher.html