KAD43 problem - Fuel, injector? (Sorry a bit long)

[msimms]

Took the boat out on Saturday and discovered a problem.

This was the first time out since the middle of last August when we came back from holiday. We were going to go out at the end off August but when I started the engine up one was very noisy. Lifted the leg and found the port exhaust bellows was dangling free. This was fixed in September, we also found the starboard bellows split. Both bellows had been replaced in June when the legs were serviced. No more pattern bellows for me!

Anyway, back to the weekend. Heading out towards Nab Tower from Chichester at 3200rpm everything was fine. As the boat hadn’t moved in six months I wanted to check if we could still pull max revs. No problems through 3400rpm and on to 3600rpm, applied a little more throttle and just as 3700rpm approached the port engine revs dropped to 2600rpm. Checked the gauges, temps and pressures were good and the same across both engines. Stopped the boat and checked the engines, all looked fine. Peered over the back but couldn’t see anything. After a couple of minutes decided to try again. Opened both throttles, a little slower than normal, and She got back on the plane. There was a momentary noise, like a single misfire. Only heard this once and it hasn’t happened since.

To achieve 3200rpm the port engine now needed more throttle and wasn’t feeling as lively as the starboard. Looking over the back there was some white smoke, not much but noticeable. I briefly opened the throttles and found the port engine could now only reluctantly achieve 3400rpm whilst the starboard rose to 3700rpm.

We headed back at 3000rpm with the white smoke still present.

Once back in the harbour and down to 1300rpm the smoke disappeared. Checking over the back the exhaust output looked clean. However, the transom, bathing platform and rear cockpit seats were covered with sooty particles. Prior to this we've never had any smoke or soot present.

As a test, with the starboard at 1300rpm I briefly opened the port to full throttle. The smoke immediately reappeared and the exhaust bubbles were black. Tried the same thing with the starboard engine, no smoke and the exhaust bubbles were not discoloured. Tried this a few times and it was always the same.

Once back on the berth I checked all the levels and all were fine. I drained off a sample of fuel from both the primary filters and although the fuel looked clean there were some suspended black particles. These were also present (and cleaned out) in December when the engines were serviced and all filters replaced. The particles were quite sizeable but there wasn’t enough of them to effect the flow. I also had similar particles present on my last boat so I thought that it was normal to get them.

I thought it a good idea to check the tank so I had a look inside the tank. I think it’s okay but not sure. When looking in to the tank the fuel has a sort of milky look to it. When I took a sample from the top of the tank and hold it to the light it looks fine. There are a couple of images below. I dosed the tank, which is around half full (250-300 litres) with 100ml of Marine 16. I may try to pull a sample from the bottom of the tank with my oil extractor to see if that also looks clean.

So, if the fuel is okay what should be the next course of action? Bad injector maybe?

Thanks for any suggestions.

Cheers

Mark

 

[PowerYachtBlog]

Check:
1) the fuel seperators, change or clean them
2) check also fuel filters (if they are due for a change)

Also try to rev the engine without load. Usually this helps to elimated fuel particles inside the engine.

 

[ulyden]

Are the boost pressure normal at both engines? (1.75bar/25psi at max power) If you have a air leakage the engine is dropping in load! Are kompressors working well?. (Boost 0.7bar 2000rpm in neutral).The white smoke can be unburned fuel wich indicate bad nozzle but it can also be steam form to hot exhaust!

Also cheeck the return diesel back to the tank! If its wery hot the fuel flow is to low and you have to cheek the lines from tank to hi pressure pump!

The withe and black smoke is confusing!

Cheeck the temperature on the sea water entering the exhaust!

It shuld not be to hot. 40-60deg! If hotter circulation to low!

This shuld not have any big infuense on the power but can kill your engine!

 

[spannerman]

Thers a much simpler way to check whats going on, get a 17mm spanner and a few rags and run one engine at around 1000rpm and slacken the injector pipe at the injector until it starts to leak out, you will hear the engine fall in rpm as one cylinder drops out and it will run a little unevenly, when you retighten the pipe it will pick up and run smoothly. If a particular cylinder doesn't produce a rev drop or the engine runs exactly the same with the pipe slackened then you have found your duff injector. Run the engines one at a time so you can hear better whats happening.
I'd advise you to have some safety glasses and maybe some gloves, its not dangerous but best to be safe then get some diesel in your eye, so hold the rag over the injector to catch any diesel, its not going to be like a fire hose, just a small squirt.
If all the injectors check our OK then you need to check plastic air pipe going from the manifold to the ecu beside the fuel filter, slacken the union being careful not to lose the olive on the pipe and check if there is any water in it, if so you can blow it out but there is a possibilty the pressure sensor has been damged, this tells the ecu if the engine is under boost or not, you really need then to have the Vodia connected to run a live date test to see if its measuring boost. The sensor can be replaced, Volvopaul has done this before so you could pm him.

 

[ulyden]

If all the injectors check our OK then you need to check plastic air pipe going from the manifold to the ecu beside the fuel filter, slacken the union being careful not to lose the olive on the pipe and check if there is any water in it, if so you can blow it out but there is a possibilty the pressure sensor has been damged, this tells the ecu if the engine is under boost or not, you really need then to have the Vodia connected to run a live date test to see if its measuring boost. The sensor can be replaced, Volvopaul has done this before so you could pm him.

Sorry I thought the 43 had a membrane smoke limiter and mechanical fuel pump!

 

[DavidJ]

The 43 has a supercharger and a turbo (no ecu but an electronic speed sensor for the supercharger). Sounds like the supercharger is OK but from your RPM data it's about when the turbo takes over. I've only had a very temporary similar'ish problem with one of my 43's and my reckoning was that the turbo shaft stuck and after a few seconds unstuck itself. Not done it but I think the turbo shaft and blades are easy to get at...others may be able to help here.
best of luck.

 

[Peanuts]

Hi

Looking at the picture of the fuel sample, what is that at the bottom of the bottle in the fuel? If that is just a sample from a drain off from a fuel filter I think that is probably where your problem comes from.

 

[KevB]

Hi Mark,

I have the tea leaf things in my primary filters, they can't get sucked up from the fuel tank because the bottom of the pick up pipes are fitted with a fine wire gauze.

I had a similar problem a couple of years ago with one engine not pulling full revs, the wire gauze on the pickup pipes had over the years got blocked. It only takes 5 minutes to remove the pipes, wash the end with petrol and put them back in.

Doesn't explain the soot though which I assume is a result of over fueling so could be a problem with the turbo. Not sure how an injector not working would cause soot, the cylinder would be starved of fuel not over fueled?

 

[spannerman]

Sorry mixing 43's with 44's, but still never heard of a smoke limiter membrane giving trouble in 28 yrs on volvos, but there is always a first time.

 

[volvopaul]

As the boat has been stood for periods it may be a sticking injector which if open will give smoke, poor atomisation white smoke etc.

I would not have tried to have run it flat out after the first time.

The early kad 42 engines had problems with faulty injectors which in turn wrecked some engines as they melted to tops off the pistons, damaged the bores etc.

I would get all the injectors removed and tested, if you have iffy fuel then I would get both engines done.

Im surprised your dealer didnt advise after changing your filters that a problem may occur in the near future, I know he cant have a crystall ball but dirt usually leads to problems and fuel pumps and injector dont like water.

 

[msimms]

Hi Mark,

I have the tea leaf things in my primary filters, they can't get sucked up from the fuel tank because the bottom of the pick up pipes are fitted with a fine wire gauze.

I had a similar problem a couple of years ago with one engine not pulling full revs, the wire gauze on the pickup pipes had over the years got blocked. It only takes 5 minutes to remove the pipes, wash the end with petrol and put them back in.

Doesn't explain the soot though which I assume is a result of over fueling so could be a problem with the turbo. Not sure how an injector not working would cause soot, the cylinder would be starved of fuel not over fueled?

Hi Kevin,

My pick-ups are welded in to the tank and can't be removed. I couldn't see the bottom of the pick-up so don't know if they have the gauze or not. Think I may have to drain out the tank and have a look. Trouble is there's about three hundred litres in there.

I don't think it's the turbo as the white smoke and dirty exhaust became apparant around 2200 - 2500 rpm. Would the turbo be doing much at those revs?

Cheers

Mark

Cheers

Mark

 

[DavidJ]

Hi Kevin,
I don't think it's the turbo as the white smoke and dirty exhaust became apparant around 2200 - 2500 rpm. Would the turbo be doing much at those revs?

I've just had a look at the spec and although the turbo is rotating all the time, it's effect won't really be noticed until the supercharger is completely off at about 3100RPM. Never say never but you are probably right. It would have been a far too a simplier solution anyway!!

 

[msimms]

As the boat has been stood for periods it may be a sticking injector which if open will give smoke, poor atomisation white smoke etc.

I would not have tried to have run it flat out after the first time.

The early kad 42 engines had problems with faulty injectors which in turn wrecked some engines as they melted to tops off the pistons, damaged the bores etc.

I would get all the injectors removed and tested, if you have iffy fuel then I would get both engines done.

Im surprised your dealer didnt advise after changing your filters that a problem may occur in the near future, I know he cant have a crystall ball but dirt usually leads to problems and fuel pumps and injector dont like water.

Hi Volvopaul,

It has been stood for a while, since August it moved from the berth to crane for a lift to have the exhaust bellows sorted. I ran the engines up on the berth prior to the oil change in Decemeber (30 mins around 1500rpm in gear alternating between fwd and reverse).

The fuel drained off from the primary filters in December contained suspended black particles. I cleaned the filters and inside the filter body. There was slightly more than the previous years but the boat had done a rough summer channel crossing so I put it down to the fuel having been sloshed around more than normal. Previous boats have always had these 'tea leaves' present. I always add an additive when fueling, and have changed from Soltron to Marine 16 last season. The tea leaves were not present above the primary filter nor in the secondary filters so I guess the primarys are doing there job.

Do you not see this in primary filter often?

I'll take your advice and get the injectors tested as the next course of action. Does removal require specialist knowledge or any special tools?

Thanks

Mark

 

[msimms]

Hi

Looking at the picture of the fuel sample, what is that at the bottom of the bottle in the fuel? If that is just a sample from a drain off from a fuel filter I think that is probably where your problem comes from.

Hi,

The fuel was pulled of direct from the tank. There's nothing in the bottom of the bottle it's just the shape and the angle of the image. Looking down in to the tank it all looks a bit murky. I think this is probably due to the light, or rather lack of it.

I did pull off a sample from the drain on the primary filters. This sample did have some tea leave type particles present. These have always been present and I thought they were normal. I've got two samples at home, one from the port filter the other from the starboard. I've dosed one with marine 16 to see if it dissolves the tea leaves.

Cheers

Mark

 

[msimms]

Check:
1) the fuel seperators, change or clean them
2) check also fuel filters (if they are due for a change)

Also try to rev the engine without load. Usually this helps to elimated fuel particles inside the engine.

The filters were all new or cleaned in December and this was the first trip out since. I'll clean up the primarys again and replace the secondarys to be on the safe side.

Cheers

Mark

 

[volvopaul]

Hi Volvopaul,

It has been stood for a while, since August it moved from the berth to crane for a lift to have the exhaust bellows sorted. I ran the engines up on the berth prior to the oil change in Decemeber (30 mins around 1500rpm in gear alternating between fwd and reverse).

The fuel drained off from the primary filters in December contained suspended black particles. I cleaned the filters and inside the filter body. There was slightly more than the previous years but the boat had done a rough summer channel crossing so I put it down to the fuel having been sloshed around more than normal. Previous boats have always had these 'tea leaves' present. I always add an additive when fueling, and have changed from Soltron to Marine 16 last season. The tea leaves were not present above the primary filter nor in the secondary filters so I guess the primarys are doing there job.

Do you not see this in primary filter often?

I'll take your advice and get the injectors tested as the next course of action. Does removal require specialist knowledge or any special tools?

Thanks

Mark

Hi MARK, yes you get the black gunge in the prefilters, if you are a basic handyman you can remove the injectors , but to prise them out of the copper sleeve you can make do without the proper tool but beware, if the sleeve comes with it you will get water in the bores.

The special tool holds down the sleeve and prizes the injector upwards away from it, its usually held in with carbon on the injector nozzle, years of build up.

Other than 13mm socket to undo retainer nuts and spanner for spill rail, 17mm for injector pipe nuts, turn off fuel supply and return, get cloth or paper to collect diesel from spill rail etc.

Its good practise to totally remove the pipes all together as bending them away from the injector is not a good idea.

Lastly, use a reputable Bosch agent that understands marine application.

 

[ulyden]

Sorry mixing 43's with 44's, but still never heard of a smoke limiter membrane giving trouble in 28 yrs on volvos, but there is always a first time.

I was thinking of the fuel limitations. If the boost disappears the power goes down and just al little black smoke is visible. Like the owner describes!

Isn’t it normal when a nozzle is defect that the idling sound and smoke is affected?

Why not check the return flow? If you take it to a bucket you can check the amount approx 2 times the full flow circulating and you can check if there are air bubbles in the fuel. If this is ok you can check the inlet pressure to the fuel pump 0.3-0.4bar at idling speed but I don’t think its necessary! You should also check that the hose to the fuel tank is opened by blowing air into it!


I sometimes test defect nozzles on new engines. The experience even totally worn nozzles are working fine just giving white smoke and less cylinder power! Problem is metal particles blocking the holes. That gives higher injection pressure and less cylinder power! But no black smoke!

I don’t understand why not all turbocharged engines have a boost gauge. Then you can observe if the things are normal or what load you have on the engine! Maximum boost at 2500rpm at full torque is 1.45bar. At full speed 1.75bar

Compressor is in 1700revs and out 2600 +/- 50rpm

Probably this thing is coursed by the nozzles but I still don’t understand why not start with the simple tings like cheking the fuel flow and measure the boost! The problem can be a lot of things even old rubber from the old exhaust bellow blocking the exhaust outlet in the drive!

An air leakage, exhaust leakage, damaged or burned valve, a blocked air filter ,or intercooler, a foreign particle in the turbo , piston ring failure can cause this also.

But I always start with the simple tings like fuel flow, throttle cables, smoke limiter, boost pressure ,air leakage. Then I start taking out nozzles or cylinder heads!

Some days ago the guys on the other side of the steet was struggling starting a brand new engine. The whole day they had been checking timing valves nozzles and so on. In the end they asked me for help. I was monitoring the start and could se the boost pressure went negative.

I asked them to remove some hatches on the air receiver and try again!
The engine started and the reason? They had forgotten to remove the embalsje on the turbo!