#1 cyl at TDC. Valves closed. Cam pulley 180deg off... HOW?! Lombardini LDW 903 Dsl

[Rumpi]

There should be no fuel on the return line when at injection point. You see fuel on the return you are not injecting. Read text next to fig. 182 and 183.

[Capt Gill]

Is this the manual you're referencing? 5th Edition

[777funk]

Got everything back together. I'm glad I had dial indicator reference points for injector fuel quantity balance because there was no way to put the injectors in exactly the same place. Set them back up with quantity and timing settings and it starts and runs smooth.

I experimented a bit and found that the engine starts easier with fuel delivery a few degrees advanced from how it was. I can get it to start without glow plugs at 55F outside. Couldn't do this before. It also catches a little sooner when restarting. I believe the exhaust smells like better burning.

But power is still not there. I'm seeing a wet fuel line from pump to filter. I may cut this line and tee a gauge in here to see what supply pressure looks like. My English translation of metric says it should be around 7psi at 3000 rpms. Hopefully it's dropping to 0 under load and this is my problem. There is no black smoke, so I would suspect it may be the issue.

[skipperpete]

The forum should be eternally grateful to 777funk for capably demonstrating why this series of Lombardini engines have no place aboard a cruising yacht....... and he doesn't have a heat exchanger and water pump">raw water pump to make this engine even more problematic.
Keep it in agricultural machinery on land where there exists an abundance of clever and patient diesel mechanics.
Maybe you folks who have one in a generator or as a main propulsion engine will eventually end up going through similar issues as the OP.

[777funk]

SkipperPete, so far, I haven't found any reliability issue. I have only investigated potential problems searching for my power issue and all systems have checked out fine thus far.

On a yacht, I would pass on this series of Lombardini engines due to the fact that this has a timing belt vs gear drive. Newer models are gear drive AFAIK. But back to the FOCS / LDW series engines, the ALL mechanical injection system is simple and robust. I'd venture to say simpler and with less parts than any other diesel injection system I'm aware of (electonic common rail or HEUI, rotary pump, inline pump).

I can't see anything mechanically wrong with the Lombardini design as a whole.

As mentioned earlier, I am not a fan of the pdf manual. But it's free and it sure beats no manual! I also don't care for the confusing TDC marking with rotation angle markings different on both pulleys on the crank. I certainly wouldn't want to wonder about all this and some basic lack of following convention (timed by exhaust stroke) as a mechanic at sea.

But... I won't beat up on the quality of the engine. It has many hours and still has over 400 psi of compression. Pretty good in my book!

[Rumpi]

The friggin engine is not timed on the exhaust stroke. And no, it's nit more complicated then other engines.
What does it mean it lacks power, dies she not rev up?

[777funk]

Originally Posted by Rumpi

The friggin engine is not timed on the exhaust stroke. And no, it's nit more complicated then other engines.
What does it mean it lacks power, dies she not rev up?

The cam mark lines up when the crank mark (and piston TDCs) on the exhaust stroke. At least mine does (came this way).

This is correct... No?

And yes lacks power. Runs out of steam under load. No black smoke. I believe this means no fuel.

[777funk]

Just put a fuel pressure gauge on it. I have 10psi upon shutdown and 5 psi with near full throttle and load (which almost kills the engine).

[777funk]

I adjusted the governor screw and can now get it to black smoke (more fuel on heavy load). However, I turned this back down since it didn't add any more power.

With the engine having 405 to 425 psi of compression, I'd say it's probably in good condition. I'm guessing, if anything, either the injectors may need to be replaced (or new nozzles) or maybe it just isn't enough horsepower for the application. It's interesting because the original gas (petrol) engine that it replaced was 21 then 25hp (later models). This one is rated at 20.9 hp so it should be close. Higher is always better, but the additional diesel torque should count for something.

That said, I did advance the timing (injection timing) a few degrees as my only change to how I received the used engine. It starts without glow plugs now and also has the proper exhaust smell for a diesel. No more unburned raw fuel smell.

[777funk]

I put a warmer thermostat in today (195F) and it seems to have a little more power. I may advance the injection timing a few more degrees and see what happens.

[Capt Gill]

Seems like you're on your own here, although I do enjoy reading your tweaking efforts on that oddball marine engine. As for power, hotter is better as long as it's within mfg. spec's, eh, unless it's raw-water cooled then you're limited to 140*F.

[777funk]

I ran it with the throttle up a bit with the latest adjustments and it is doing better. Changes made:

-2 to 3 degrees further advanced injection (from how I received it - starts easier now)
-governor screw adjusted for a little more fuel under load
-195F thermostat
-throttle higher

I can now drive it full speed (hydrostat) going up hills.

I believe the engine is right on the border line HP wise (21HP in a 3600 lb skid steer). Most similar skid steers have 35HP diesels or better.

To all... thanks for the support. I like the design of the engine and it's injection system. It's about as simple as it gets and the sensors and warning lights (oil, temp, air, battery) are great. This is the only place I could find help and info on the engine. Great and knowledgeable forum members here!

[Wotname]

^^ thanks for creating the thread 777funk, I have enjoyed following your progress with this engine.

[Capt Gill]

Wait a minute! Looking through the posts it appears you have a raw water-cooled engine, i.e. no heat exchanger, seawater directly cools the engine, if so a running temp. of 195*F is a big no, no! Further info upon request.

[777funk]

Originally Posted by Capt Gill

Wait a minute! Looking through the posts it appears you have a raw water-cooled engine, i.e. no heat exchanger, seawater directly cools the engine, if so a running temp. of 195*F is a big no, no! Further info upon request.

I'm not familiar with the raw water systems, but it's in a skid steer (with a radiator). So there is no seawater in question. It's running coolant. I'd assume any temp up to 205F or so is pretty common and ok for operation in this case, no?


The engine original was mounted (by Lombardini from the factory I believe) to a hot water/steam pressure washer.




Additional progress... it seems to be within a few horsepower of enough to be really the perfect fit (just enough horsepower and easy on fuel) at this point. I'm considering water/methanol injection. Maybe would be a little excessive for the application, but the only other easy HP gain would be a small turbo and space confinement on the exhaust side of the engine is pretty limited here unfortunately.