Back to the UK for a winter refit

[jrudge]

Presumably a Vodia tool on the boat whilst in motion would give more of a clue of what was going on. The Throttle head is simply a potentiometer. You have swapped over the throttles to no effect, but these wires will run back to the ECU somewhere. I wonder if there is a connector that has got corrosion etc on it. This would reduct the voltage to the ECU and demand less power.

If you have a multimeter you could connect this to the wires from the throttle. There will be a reference voltage (5v on a cat, not sure re volvo) that should be the same on both across the outer lugs of the potentiometer, and the voltage from the middle wiper of the potentiometer should increase and decrease in line with throttle movement. Both throttle voltages should be the same give or take for a given position. If they are you could possibly then chase that same voltage level through to the input of the ECU to see if it is the same.

If RKs machine was saying only 94% demanded then I would guess ( and it is a guess) that at the ECU the voltage will not be the same as at the throttle head.

 

[jimmy_the_builder]

Presumably a Vodia tool on the boat whilst in motion would give more of a clue of what was going on. The Throttle head is simply a potentiometer. You have swapped over the throttles to no effect, but these wires will run back to the ECU somewhere. I wonder if there is a connector that has got corrosion etc on it. This would reduct the voltage to the ECU and demand less power.

If you have a multimeter you could connect this to the wires from the throttle. There will be a reference voltage (5v on a cat, not sure re volvo) that should be the same on both across the outer lugs of the potentiometer, and the voltage from the middle wiper of the potentiometer should increase and decrease in line with throttle movement. Both throttle voltages should be the same give or take for a given position. If they are you could possibly then chase that same voltage level through to the input of the ECU to see if it is the same.

If RKs machine was saying only 94% demanded then I would guess ( and it is a guess) that at the ECU the voltage will not be the same as at the throttle head.

After recalibration at RK the Vodia tool was saying 100% from the throttle, so that (on the face of it) seems to rule out the wiring/connector issue.

It's beginning to feel like I need a technician with a vodia tool on the boat to figure this one out.

 

[jfm]

As regard risers, I don't see that as the cause. The difference you made was small. But almost anything is possible - a few further diagnoisis questions:

1. is it the case that below the 3100rpm the engines are RPM matched, and then as you continue to push the sticks forward the stbd engine stays at 3100 rpm while the port engine rises to 3500rpm?
2. And at 3100rpm, is the fuel burn rate the same in both engines? If it is, then your problem isn't the riser or anything else mechanical. If however the stbd engine is taking the max fuel burn rate at 3100rpm that the ECM will allow, ie the same burn rate as the port engine takes at 2500rpm, then something is making stbd engine work harder or burn fuel less well, and one possible though still very unlikely culprit is the exhaust system. I repeat - unlikely. There's a suppose a million-to-one chance that the diy mod introduced a pressure wave profile that, by coincidence, is interfering with gas flow and/or turbo speed. Also I'd expect you would see smoke though I don't know how well your exhaust system buries smoke

Yep, you need a vodia wielder on board to find out what's going on. Need to know what fuel is going in, and what the compressed inlet air parameters are

Were the injectors touched during the refit?

Vas, there are no governors that have a "position" on these engines. It is all electronic. The ECM reads the rpm demanded by the driver, and it reads the rpm being achieved using proximity sensors that sense the flywheel gear teeth or something similar. The ECM then tells the fuel injectors to open for slightly more nanoseconds if it wants a higher achieved rpm and slightly fewer nano seconds if it wants to drop the achieved rpm. There is therefore no governor "position" and no centrifugal weights. It's all inside the ECM.

 

[jimmy_the_builder]

As regard risers, I don't see that as the cause. The difference you made was small. But almost anything is possible - a few further diagnoisis questions:

1. is it the case that below the 3100rpm the engines are RPM matched, and then as you continue to push the sticks forward the stbd engine stays at 3100 rpm while the port engine rises to 3500rpm?
2. And at 3100rpm, is the fuel burn rate the same in both engines? If it is, then your problem isn't the riser or anything else mechanical. If however the stbd engine is taking the max fuel burn rate at 3100rpm that the ECM will allow, ie the same burn rate as the port engine takes at 2500rpm, then something is making stbd engine work harder or burn fuel less well, and one possible though still very unlikely culprit is the exhaust system. I repeat - unlikely. There's a suppose a million-to-one chance that the diy mod introduced a pressure wave profile that, by coincidence, is interfering with gas flow and/or turbo speed. Also I'd expect you would see smoke though I don't know how well your exhaust system buries smoke

Yep, you need a vodia wielder on board to find out what's going on. Need to know what fuel is going in, and what the compressed inlet air parameters are

Were the injectors touched during the refit?

Vas, there are no governors that have a "position" on these engines. It is all electronic. The ECM reads the rpm demanded by the driver, and it reads the rpm being achieved using proximity sensors that sense the flywheel gear teeth or something similar. The ECM then tells the fuel injectors to open for slightly more nanoseconds if it wants a higher achieved rpm and slightly fewer nano seconds if it wants to drop the achieved rpm. There is therefore no governor "position" and no centrifugal weights. It's all inside the ECM.

The basic aspiration profile of the engines, as I understand it, is that 0-1500 rpm is normal aspiration; 1500-2500 is supercharged; 2500-3500 (wot) is turbocharged. Rpm response 0-2500 is the same between the two engines; above 2500 the stbd engine lags the port engine.

I don't have any fuel consumption data (this is the much-discussed 'trip computer' software upgrade which is £1k+ for my installation, and which I consequently don't have; VP's pricing on this upgrade is barmy - if it was £200 we'd all have it).

I've been in touch with RK Marine again this morning and they are similarly of the opinion that the riser mod is very unlikely to be the culprit. Based on the same info that I've given here they are suggesting issues either with fuel delivery (pipe kinked or in some other way compromised on reinstallation) or (more likely) some reassembly failure around the turbo that is causing boost pressure loss.

Injectors were not touched during refit.

I think the way forward is a sea trial with a Vodia person - either I take someone from RK or SSL down, or more sensibly, I get someone from Sud Diesel in Antibes. I've sent SD an email to ask the question - it'll be interesting to see if I get a reply.

 

[henryf]

I've only read the last bit of this thread but from what you describe it sounds turbo related. Assuming nothing mechanically wrong with the turbos the a leak somewhere or a sticking actuator (if they have them).

Am I right in thinking that the intake is all metal - to rule out a collapsing pipe under vacuum.

Henry

 

[jfm]

Yup sounds correct Jimmy. Based on that aspiration it sounds like turbo. Data from vodia would be nice, if it's comprehensive. Is there a wastegate and how is it actuated?

Sud diesel shd be ok - you'd expect they're all busy right now but I've got a Cat Service from the Cat shop later this week, booked with only 10 days lead time. Monaco Marine at SLDV is also Volvo agent I think

 

[jimmy_the_builder]

I've only read the last bit of this thread but from what you describe it sounds turbo related. Assuming nothing mechanically wrong with the turbos the a leak somewhere or a sticking actuator (if they have them).

Am I right in thinking that the intake is all metal - to rule out a collapsing pipe under vacuum.

Henry

Yup sounds correct Jimmy. Based on that aspiration it sounds like turbo. Data from vodia would be nice, if it's comprehensive. Is there a wastegate and how is it actuated?

Sud diesel shd be ok - you'd expect they're all busy right now but I've got a Cat Service from the Cat shop later this week, booked with only 10 days lead time. Monaco Marine at SLDV is also Volvo agent I think

Here's a pic of a similar engine: turbo is nearest the camera; the blue tape is covering up the flange on to which the modified riser is fitted. You can see the inlet air route from the air filter to the turbo.

One practical issue is that the turbo on the stbd engine is extremely tricky to get at - it is the least accessible part of the entire installation. I guess I will have to cross that bridge when I get to it.

Sud Diesel have replied (and phoned) but they don't want to answer my 'what is your hourly rate' question. Instead they are going to write to me with a formal quotation for two hours work to cover the sea trial...

 

[jfm]

What does exhausts gas look like? Smoke?

Formal quote seems normal. They love pushing paper around. The cat dealer discloses hourly rate on my cat quotes and invoices. e85/hour HT

 

[petem]

Here's a pic of a similar engine: turbo is nearest the camera; the blue tape is covering up the flange on to which the modified riser is fitted. You can see the inlet air route from the air filter to the turbo.

One practical issue is that the turbo on the stbd engine is extremely tricky to get at - it is the least accessible part of the entire installation. I guess I will have to cross that bridge when I get to it.

Sud Diesel have replied (and phoned) but they don't want to answer my 'what is your hourly rate' question. Instead they are going to write to me with a formal quotation for two hours work to cover the sea trial...

Jeez, JTB, is that your house? Bit rubbish innit?

 

[DAW]

The Volvo engineer who services the D12-715s on my boat in Beaulieu also refuses to quote hourly rates for engine/gearbox related work, but seems to average e85-90/hour HT and is usually able to respond to "urgent" ad-hoc requests within 72 hours even at this time of year.

 

[Hurricane]

Stupid thought
Didn't we have a similar question on here a year or so ago.
It turned out to be the gauge - not the engine.
I suppose it isn't the obvious??
I'll shut up now.

 

[tico]

J
Strangely enough I had the same thought as Hurri, but supposed that you could hear/feel the difference in revs.

It may be a wild suggestion but I had a similar problem a while back with one of my KAD43s.
Turned out that the squashy rubber gasket from the air pipe had fallen down into the supercharger and had deposited sticky rubber on the compressor blades. I cant explain why it should affect the engine revs at a time when the supercharger shouldn't be working and the turbo taking over..
All that I can say is that following removal and an hour or so carefully cleaning the supercharger impellor (not really blades, but you know what I mean) with white spirit and clean rags. all was well again and full revs achieved.

 

[jimmy_the_builder]

What does exhausts gas look like? Smoke?

Formal quote seems normal. They love pushing paper around. The cat dealer discloses hourly rate on my cat quotes and invoices. e85/hour HT

Nothing untoward (as far as you can tell - with the outdrive installation the exhaust outlet is in the leg, underwater).

That hourly rate is about the same as RK Marine, funnily enough.

 

[jimmy_the_builder]

Jeez, JTB, is that your house? Bit rubbish innit?

Tee-hee, no it is just some random picture I found on the web...

 

[jimmy_the_builder]

The Volvo engineer who services the D12-715s on my boat in Beaulieu also refuses to quote hourly rates for engine/gearbox related work, but seems to average e85-90/hour HT and is usually able to respond to "urgent" ad-hoc requests within 72 hours even at this time of year.

Must be a cultural thing I guess. Is that Monaco Marine by any chance?

 

[jimmy_the_builder]

Stupid thought
Didn't we have a similar question on here a year or so ago.
It turned out to be the gauge - not the engine.
I suppose it isn't the obvious??
I'll shut up now.

I'd be surprised if it was the gauge because there's more than one indicator - revs, speed, and lever position. If it was just one of those three things then the troubleshooting approach would be different.

 

[DAW]

Must be a cultural thing I guess. Is that Monaco Marine by any chance?

Not Monaco Marine, but a local Volvo Penta service centre based in Beaulieu and working the coast from Monaco to Cannes. Was highly recommended by Sunseeker France and has looked after us for three years now. The main guy speaks fluent English, is switched on, reliable and responsive and is willing to work with UK OEM/parts suppliers to keep costs down. Annual servicing is same price as UK, which makes a pleasant change for SoF.

 

[RogerRat]

I had a similar power loss on the Azi last summer that Col sorted.
1. Dirty filters from old fuel and yes they were new ish, replaced, inmproved from about 70 -75%
2. Sticky throttle position sensor giving a limited voltage on the diagnostics. 75-85% improvement.
3. There was as en extraneous voltage from a poor relay contact that was inclose proximity to the micro commander.

All 3 items had to be sorted to get back to full power. I know they're Cats' and not VP but the 'Vodia' man should be able to find something similar for sure. The strange bit is no audible warning which means the Vodia may not pick it up as a fault after all.

Looking forward to hearing outcome now. :encouragement:

RR

 

[jimmy_the_builder]

Not Monaco Marine, but a local Volvo Penta service centre based in Beaulieu and working the coast from Monaco to Cannes. Was highly recommended by Sunseeker France and has looked after us for three years now. The main guy speaks fluent English, is switched on, reliable and responsive and is willing to work with UK OEM/parts suppliers to keep costs down. Annual servicing is same price as UK, which makes a pleasant change for SoF.

Sounds like a strong recommendation; could you post (or pm) contact details please? I can't see a VP service centre in BSM on the VP France website.

 

[jimmy_the_builder]

I had a similar power loss on the Azi last summer that Col sorted.
1. Dirty filters from old fuel and yes they were new ish, replaced, inmproved from about 70 -75%
2. Sticky throttle position sensor giving a limited voltage on the diagnostics. 75-85% improvement.
3. There was as en extraneous voltage from a poor relay contact that was inclose proximity to the micro commander.

All 3 items had to be sorted to get back to full power. I know they're Cats' and not VP but the 'Vodia' man should be able to find something similar for sure. The strange bit is no audible warning which means the Vodia may not pick it up as a fault after all.

Looking forward to hearing outcome now. :encouragement:

RR

The thing about bad fuel flow on EVC is that you'd definitely get a warning (I've had it before). I might change the prefilters again just to be 100% certain.