Tuning Volvo Penta 2003

[Swizzle Stick]

Hi all.

I've owned my boat for less than six months but haven't been able to use it as often as I'd like due to Covid lockdowns. However, all is not lost as this has given me some time to get to know the systems onboard and muck about with the engine.

I have a Volvo Penta 2003 inboard (1.3L 3 cylinder 28hp diesel) with a shaft driven folding propeller. I see Mr Coriolis has done his work in the southern hemisphere as the prop spins anti-clockwise

The engine doesn't seem to use much (if any) oil and I haven't had to touch the coolant level. It has no obvious leaks and I've changed all the filters. There were a couple of small fuel leaks around the injection pumps, but I fixed them earlier today. See my other thread if you want to see how I did it - thanks in no small part to some excellent advice from others on this forum.

Yep - its an old engine - more than 30 years old. It doesn't have a tacho so I'm not sure how many hours it has on it. However, it runs well. It propels a 40ft boat along pretty well (6-7 kts) and always starts easily, even when cold.

The engine blows a bit of white smoke - mainly when cold - but it still smokes a bit when warm too. It also leaves a small sheen of fuel from the exhaust. Again, it's worse when cold but it doesn't completely go away when warm either.

I appreciate it's not a high tech engine and its not a new engine - geez 28hp from a 1.3L diesel? My car gets 308hp from a 3.0L diesel.

I'm not sure if it's clunky because it's a three cylinder, because it's old or because it's out of tune. Actually, I'm not even sure if it IS clunky - maybe that's how they all are!

I was hoping, after I fixed the small leaks from the fuel pumps the engine would run smoother (due to higher fuel injection pressure) and magically stop smoking but it seems exactly the same - minus the smelly leak of course.

So my question is, how do you tune up one of these engines and how do you know if it is in or out of tune?

I've learned you can adjust the injection timing by the thickness of the shims under the injector pumps. It looks a simple matter to experiment with thicker and thinner shims, but what are you looking for when you do it?

The engine seems pretty solid, simple and everything is mechanical. There is no idle, no mixture and obviously no spark plugs (or glow plugs). What else is there to tune on these engines?

Thanks in advance for your advice specific to this engine (and/or the other 2000 series Pentas).

[Pete7]

So this is probably a 30 plus year old engine, ours is 32

If it runs I would strongly recommend leaving it alone and give it an Italian tune up when you get the chance. This will involve nearly full revs for several hours to clear the carbon out. Ours ran much better after this, as the previous owner used to mollycoddle it with low revs and lots of tickover battery charging..

That said if you do pull the injectors for a service, they are held in place in a copper tube that has coolant around them and they are a push fit. If the injector comes out, all well and good. If the copper tube or sleeve comes out then you have a problem and may need to take the head off. The copper sleeves are still available, just. You could of course do a top end over haul, so the valves are cleaned etc.

Don't start fiddling around with the FIPs, that is asking for trouble. There is a sticky at the top of the engine forum for these engines which explains how to check the fuel rack by taking a bolt out of the rear port side of the block, might be worth checking.

Finally the exhaust manifold will eventually block with carbon and efforts to clean are not very successful as in time the cast iron also starts to break up. However, worth checking.

I ditched the VP air filter and stuck a K&N filter on because I couldn't face trying to clean the VP one with diesel.

Not sure if the freshwater cooled version has an anode, the raw water version has it behind the alternator. Did you put a new water pump impeller in it. I tend to change it every couple of years.

Not a bad engine, VP made thousands of them, many still going.

Pete

[OloteleMtn]

Valve adjustment and overhauling the injectors will help a lot usually; short of a shop overhaul of the injectors, sometimes disassembly, cleaning, and reassembly is helpful. Clean fresh fuel is a good idea also.

[Pete7]

Agreed, worth checking the fuel tank is clean especially on an old boat.

The other thing you can do for the engine is make sure the hull is spotlessly clean including the propeller. Finally go through the boat with the zeal of a Spanish inquisition and remove anything you don't need. Coastal cruising, do you really need full fuel and water tanks? We often cruise with half tanks and top the water up on arrival.

3 clyinders won't be as smooth as a 4 cylinder engine and worn engine mounts will cause it to rock at low revs, again worth checking with a crow bar to lift the feet. Alignment to the prop is another check. The mounts do settle over time. We replaced ours, not a cheap exercise unfortunately.

Pete

[Wotname]

Originally Posted by Swizzle Stick

............
However, it runs well. It propels a 40ft boat along pretty well (6-7 kts) and always starts easily, even when cold.

If it starts well when cold, then compression is good.

The engine blows a bit of white smoke - mainly when cold - but it still smokes a bit when warm too. It also leaves a small sheen of fuel from the exhaust. Again, it's worse when cold but it doesn't completely go away when warm either.

Injectors may need attention or prop / hull dirty or prop pitch is wrong.

.........

I'm not sure if it's clunky because it's a three cylinder, because it's old or because it's out of tune. Actually, I'm not even sure if it IS clunky - maybe that's how they all are!

They are clunky but if vibrating too much or shaking a bit, time to check engine mounts and prop shaft alignment.

..............
So my question is, how do you tune up one of these engines and how do you know if it is in or out of tune?

Not really any tuning, more general maintenance as detailed in other posts upthread. Valve lash, exhaust manifold, raw water pump impeller etc.

I've learned you can adjust the injection timing by the thickness of the shims under the injector pumps. It looks a simple matter to experiment with thicker and thinner shims, but what are you looking for when you do it?

Timing once set initially doesn't change and doesn't need any further adjustment.

The engine seems pretty solid, simple and everything is mechanical. There is no idle, no mixture and obviously no spark plugs (or glow plugs). What else is there to tune on these engines?

There should be an idle adjustment somewhere but usually never needs adjustment.

Thanks in advance for your advice specific to this engine (and/or the other 2000 series Pentas).

The Italian tune up mentioned upthread is always a good idea. Chuck some ATF in the tank (say 3 or 5%), it sometimes cleans up injectors if they aren't too bad.

Fit an oil pressure gauge if you want to get an idea of the condition of the bearings.

Fit a tacho or use a hand held one to see if you are correctly proped.

[olaf hart]

Don’t pull the injectors on this motor unless you are prepared for a head rebuild, the copper seals mentioned above are really tricky.
Don’t know if you have a sealed or a raw water cooling system, but this is a weak spot on this engine and needs a proper clean out and flush.
The exhaust elbow is really a maintenance item, they block easily and need to be replaced regularly. I always carry a spare and a gasket, replace it every few years, acid clean the old one and keep it spare for the next change over.
Eventually you will have to go to the bank and get a loan to buy a new one, but I have had this boat for nine years and am still getting away with rotating them.

[Swizzle Stick]

Sorry guys.

I previously advised I have no tachometer. That's not right. I have no hours meter.

The instrumentation fitted is pretty basic though: tacho (rpm only) and three warning lights - cooling water temp high, oil pressure low, alternator voltage low. The lights all go off when the engine starts and haven't yet come on at inopportune times.

The boat chugs along at about six knots at 2100 rpm but only gets to about seven knots if you push full throttle. It seems to do about 2600-2700 rpm at full throttle in gear and more in neutral. It is a pretty fancy prop and I believe a fair bit of research went into its selection.

The engine has coolant re-circulation through a seawater heat exchanger with once through seawater cooling. I have cleaned out the seawater strainer but I haven't changed the pump impeller since I bought the boat. I have a few spares so I should probably at least open up the pump and have a look.

The seawater cooling seems to work pretty well. The water fairly blasts out the exhaust, but it takes a while to get warm. I assume this is normal and occurs because the thermostat doesn't route coolant through the HX until the engine is warm.

I haven't taken the HX apart but I have been thinking of running calcium scale and rust remover through the seawater feed pipe one of these days and letting it sit in the HX. I used this stuff (sulphamic acid) to descale the discharge hose on the marine toilet (seawater flushing) and it worked a treat.

I believe the previous owner replaced the exhaust elbow not that long ago. I've heard these elbows cost a fortune. I can see myself going to a fabrication shop and getting one custom made if I need a replacement. How expensive can a 3"(?) elbow be to make?

It might also be my imagination, but I'm not sure if the engine is as smokey when underway as in neutral. Maybe just the wind blowing it away but I've never noticed a trail of smoke billowing behind while motoring.

[Ivansgarage]

Injector cleaner can do miracles on a old engine or one that has been sitting, just add it to the fuel...

[Swizzle Stick]

Thanks Pete7.

Can you please provide me details of the air filter you used. Does it go in the existing air filter casing or does it replace the casing all together?

I too thought a diesel soaked filter was a bit strange and I'm not sure what's currently in the casing - or how well it works.

[Swizzle Stick]

Thanks Ivansgarage.

I did put some expensive cleaning stuff in the fuel but I haven't been able to run it long enough yet to see if it does anything.

[Swizzle Stick]

Chuck some ATF in the tank (say 3 or 5%), it sometimes cleans up injectors if they aren't too bad.


Thanks Wotname.

By "ATF" do you mean automatic transmission fluid? I did put some Penrite injector cleaner ($$$) in the tanks but I haven't run it long enough to see what (if anything) it does.

[Wotname]

Originally Posted by Swizzle Stick

Chuck some ATF in the tank (say 3 or 5%), it sometimes cleans up injectors if they aren't too bad.


Thanks Wotname.

By "ATF" do you mean automatic transmission fluid? I did put some Penrite injector cleaner ($$$) in the tanks but I haven't run it long enough to see what (if anything) it does.

Yes.

Poor man's injector cleaner but seems to work better than the $$$ stuff.

Given the reported potential problems with pulling the VP 2003 injectors, I would be inclined to give it a couple of goes. Only downside is the additional cost of the ATF.

[Compass790]

Originally Posted by Swizzle Stick

Sorry guys.

I believe the previous owner replaced the exhaust elbow not that long ago. I've heard these elbows cost a fortune. I can see myself going to a fabrication shop and getting one custom made if I need a replacement. How expensive can a 3"(?) elbow be to make?

It might also be my imagination, but I'm not sure if the engine is as smokey when underway as in neutral. Maybe just the wind blowing it away but I've never noticed a trail of smoke billowing behind while motoring.

Don't know where in the world you are but exhaustelbow.com in North America can make you a cheaper ss. one or any place that does ss pipework I imagine. Get it made out of Sched 10 316L ss rather than tube is my tip.Will last waay longer than cast-iron. Still will need de-carbonising periodically.

Engine could well be less smokey underway as it's warmer under load so getting a better fuel burn.

[BlackHeron]

I've pulled the injectors twice on my 2003t. Had no issues. Simple job. I wonder how many of the people who repeat this stuff here have actually ever DONE it, or are just repeating what they have "heard" on the internets.

Cruisers Forum never disappoints.

[Swizzle Stick]

[QUOTE=Compass790;3183734]Don't know where in the world you are.....


Yep. It probably makes sense to add my location to my profile