Hi all, been a while since I've been active here but still been reading everyones posts.

So, I've got an issue with my engine. I've just arrived in Ambon and had some issues appearing during the past days. I'll go back to when I first noticed something.
A few weeks ago i noticed that the motor was taking a bit more cranking before it started so last week before a passage I did a service, changed all filters etc. Also did a valve clearance check and took of the heat exchanger/elbow and cleaned everything. There was some soot buildup around the exhaust ports which a cleaned away. Engine seemed to run better but still not starting as it used too but I had a good feeling about going on the passage.

Yesterday coming into Ambon we had some current against us so I was running the engine for an hour using us in. It took a while to get it going but as we'd been bashing into big waves the past 12 hours it didn't surprise me too much. Once running it didn't accelerate like normal, as in, I pushed the throttle down to my normal spot and the engine took a while to catch up which it never does. That surprised me so after it wormed up I played around a bit, trying full power and it wouldn't rev over 3000. Normally run it between 2000and 2500 but sometimes run it for a while at 3000 and it will go all the way to 3800 under load but then blows some smoke from over fueling. Now it only gets to 3000 and takes a while to even get there. I then put it in neutral and it ran perfect all the way through the rev range.

I'm personally thinking injectors, I think I'll pull them and have a look although I've never done it myself.

Any other idea's form those of you with experience?

We have another 350nm passage to do and I'd like to have bit more trust in the motor before setting off.

Thanks

>Vernon

Bushdog said..
I have the same motor (3GM30F).
You seem to have two issues that may or may not be related.
1. Slow to start. Is it turning over slower, or at usual speed but for longer?
2. Reduced power/reduced responsiveness.

Some thoughts:
You have a folding prop? It's easy to exclude a fouled/jammed prop as cause for power loss by hopping over the side for a look.
You could have a minor air leak after the filter changes e.g. one of the Small copper washers at the engine filter could be badly seated or scored.
Any possibility that you got some dud fuel?
if its worn injectors you'd likely see more unburned fuel at lower working revs. Pulling the injectors may show more unburned gunk around one injector. Alternately, pulling one at a time, reconnecting it and turning the motor over may identify one blocked/part blocked injector.
Alternately, there should be a diesel mechanic around with simple testing gear to check at what pressure the injectors open and how they spray. Keep in mind that you should replace injector washers when you remove em. You don't want to go pulling injectors off, find nothing and create more issues/delays.
You could try some injector cleaner/decarboniser before reaching for the spanners.

Good luck, and tell us how you get on.

Hey BD and thanks for your ideas.

1. turning over as normal but cranking longer before firing up.

Yes, had thought about something fouling the prop, other times its happened I've always felt vibration. I'll jump in tomorrow and give it a check though as it would be the easiest fix.
Yes, you're right, a tiny air leak would make sense as the engine runs fine with no load but struggles when in gear.
Dud fuel is always a possibility in Indo but then I would expect to see water/sludge in my filters. There was a tiny bit of water in the bottom of the bowl but thats normal I think.
There is someone here that can do injector tests but I'm not sure that there would be new washers here in stock.

Stockie said..
Hi Vernon,

long time since we heard from you, but glad you are near land now!
as a generalisation, if the engine characteristics changed quickly, with what you have described, it sounds like an outside influence. IE fuel quality, or extra load on the engine. As the other responder advised, check your fuel lines for leaks or sucking air and put some injector cleaner in first. The general engine performance from soot or carbon should be a gradual deterioration.
Maybe check the sail drive oil too?

cheers Richard

Yeah good stuff Stockie, make sense.
I forgot to mention the sail drive. I checked the oil when I did the service and it was sort of pressurised, as in when I undid the bung oil came up out of the hole. It was clean oil and I just put the cap back on. Is that normal? I've not noticed anything different about the drive though, vibrations, extra heat etc.

Injector cleaner I've never used. I guess the engine would have to burn through a tank of fuel to make a difference?

Dexport said..

Stockie said..
Hi Vernon,

long time since we heard from you, but glad you are near land now!
as a generalisation, if the engine characteristics changed quickly, with what you have described, it sounds like an outside influence. IE fuel quality, or extra load on the engine. As the other responder advised, check your fuel lines for leaks or sucking air and put some injector cleaner in first. The general engine performance from soot or carbon should be a gradual deterioration.
Maybe check the sail drive oil too?

cheers Richard

Yeah good stuff Stockie, make sense.
I forgot to mention the sail drive. I checked the oil when I did the service and it was sort of pressurised, as in when I undid the bung oil came up out of the hole. It was clean oil and I just put the cap back on. Is that normal? I've not noticed anything different about the drive though, vibrations, extra heat etc.

Injector cleaner I've never used. I guess the engine would have to burn through a tank of fuel to make a difference?

Dexport said..

Stockie said..
Hi Vernon,

long time since we heard from you, but glad you are near land now!
as a generalisation, if the engine characteristics changed quickly, with what you have described, it sounds like an outside influence. IE fuel quality, or extra load on the engine. As the other responder advised, check your fuel lines for leaks or sucking air and put some injector cleaner in first. The general engine performance from soot or carbon should be a gradual deterioration.
Maybe check the sail drive oil too?

cheers Richard

Yeah good stuff Stockie, make sense.
I forgot to mention the sail drive. I checked the oil when I did the service and it was sort of pressurised, as in when I undid the bung oil came up out of the hole. It was clean oil and I just put the cap back on. Is that normal? I've not noticed anything different about the drive though, vibrations, extra heat etc.

Injector cleaner I've never used. I guess the engine would have to burn through a tank of fuel to make a difference?

My saildrive pressurises, so no issue there I do t think, but it should not be over filled. Just a puff off pressure when you undo the dipstick. If the oil is not milky, ALLGOOD.
I put crap fuel in my engine and it lost power, and would not rev. Poured in some injector cleaner and 20 litres of good diesel and she came right, quiet quickly. That's the first thing I would suggest, before getting the spanners out! A fuel blockage in the feed line is another serious possibility. I'm thinking even an insect or such like. If you have source of compressed air, you could try blowing it from ahead of the fuel filter back to the fuel tank. Even an inflatable pump would work. Any resistance would indicate a blockage.
The longer than normal crank times when cold could also be a dud glow plug. Does she start better when hot?

Ive had similar problems on a 3qm30 caused by a miniscule leak before the injector pump.

ramona is correct ,it is a air leak at your primary air filter,if it is a racor with a cartrige in it they are very hard to seal up and the filter should only be genuine,i always remove the whole asembly to change the filters and vacume test before puting on . check this before you pull any injectors.i doubt you have a injection problem

Dexport said..

grich62 said..
ramona is correct ,it is a air leak at your primary air filter,if it is a racor with a cartrige in it they are very hard to seal up and the filter should only be genuine,i always remove the whole asembly to change the filters and vacume test before puting on . check this before you pull any injectors.i doubt you have a injection problem

Thanks for the great advice. Turns out I'm an idiot!
I put an O-ring on the top of the water separating filter that was slightly too big and it squeezed out to the side a little, allowing some air in. Changed it out for the correct one, bled the system and she was all good, motor runs like a charm now. As it had been starting badly I just thought that had something to do with it but when I changed out the filters I had probably fixed the bad starting but created a new problem at the same time.
Anywho, nice to know you all give good advice and I was able to figure this minor issue out without pulling my engine apart.

i would bet your intial bad starting was also a smaller leak in these filters,they are the hardest filter that i have seen in my 43 years of diesel fitting.Here is somthing to think about,can you change that filter in a big sea while being blown towards a reef,There are beter filters avaliable with spin on filters that can change quick and easy.

grich62 said..

Dexport said..

grich62 said..
ramona is correct ,it is a air leak at your primary air filter,if it is a racor with a cartrige in it they are very hard to seal up and the filter should only be genuine,i always remove the whole asembly to change the filters and vacume test before puting on . check this before you pull any injectors.i doubt you have a injection problem

Thanks for the great advice. Turns out I'm an idiot!
I put an O-ring on the top of the water separating filter that was slightly too big and it squeezed out to the side a little, allowing some air in. Changed it out for the correct one, bled the system and she was all good, motor runs like a charm now. As it had been starting badly I just thought that had something to do with it but when I changed out the filters I had probably fixed the bad starting but created a new problem at the same time.
Anywho, nice to know you all give good advice and I was able to figure this minor issue out without pulling my engine apart.

i would bet your intial bad starting was also a smaller leak in these filters,they are the hardest filter that i have seen in my 43 years of diesel fitting.Here is somthing to think about,can you change that filter in a big sea while being blown towards a reef,There are beter filters avaliable with spin on filters that can change quick and easy.

grich....I'm interested in the spin on type CAV filter, do you have experience of these ?. Where do you get replacement elements from ?.
Thanks mate.

Next time you need a filter replacement just wander into Supercheap and by a Ryco water filter separator. Superb quality Chinese alloy castings. Impossible to screw up the O rings and the fit is a 100% better than a Cav298 or a Racor 500.

www.rycofilters.com.au/Universal_Fuel_Water_Separators

samsturdy said..

grich62 said..

Dexport said..

grich62 said..
ramona is correct ,it is a air leak at your primary air filter,if it is a racor with a cartrige in it they are very hard to seal up and the filter should only be genuine,i always remove the whole asembly to change the filters and vacume test before puting on . check this before you pull any injectors.i doubt you have a injection problem

Thanks for the great advice. Turns out I'm an idiot!
I put an O-ring on the top of the water separating filter that was slightly too big and it squeezed out to the side a little, allowing some air in. Changed it out for the correct one, bled the system and she was all good, motor runs like a charm now. As it had been starting badly I just thought that had something to do with it but when I changed out the filters I had probably fixed the bad starting but created a new problem at the same time.
Anywho, nice to know you all give good advice and I was able to figure this minor issue out without pulling my engine apart.

i would bet your intial bad starting was also a smaller leak in these filters,they are the hardest filter that i have seen in my 43 years of diesel fitting.Here is somthing to think about,can you change that filter in a big sea while being blown towards a reef,There are beter filters avaliable with spin on filters that can change quick and easy.

grich....I'm interested in the spin on type CAV filter, do you have experience of these ?. Where do you get replacement elements from ?.
Thanks mate.

sorry woko ive been out on the boat no internet ,most spin on filters based on nissan ,toyota avalable from parts shopes are good and cheap and deal with fuel flows for low horsepower engines,be carefull of large filters with high fuel flows as fuel flow is low.the filter ramona recomends is good to