Volvo Tamd74P won't rev passed 2000 rpm

[Alanarkison]

Fairline phantom 43 with twin Tamd74P engines. Bought with a known fault that both engines wont rev passed 2000 RPM with morse lever all the way ahead. Engines just get to about 70% and then there's no more. Previous engineer changed injectors, fuel pump, turbo chargers and boost sensors. They were using Jaltest to connect to the ECU but thought that the fuel pump rod was 100% WOT but we've had the local Volvo engineer down today and plugged in with Vodia to both engines and it showed max fuel rod position of 67% with morse lever full ahead. No fault codes shown so my thinking is that the EDC would call a fault if the fuel rod isn't where it should be or if the actuator wasnt moving the rod correctly ( codes 2.2 and 2.3). So the EDC thinks that the fuel rod should be where it is. Ive attached the picture of the scan. boost pressure seems normal at 185 KPA (27psi) for 1900 rpm. Interestingly relative load is at 100% with only 1912 rpm and 67% fuel rod position. EDC only restricts fuel on air inlet temperature (27 deg C) or boost pressure ( 27 psi) but both seem ok. Im thinking this is software related and that the EDC may need the software reloaded. Does anyone have any other ideas.

 

[Seastoke]

What did the vp engineer say.

 

[Alanarkison]

He thinks the fault is electrical/electronic either a sensor or EDC, but doesn't have much experience with older EDC. He has more experience with the new EVC's. They had to order the cable in as they hadn't connected to an older EDC before.

 

[Alanarkison]

Fairline phantom 43 with twin Tamd74P engines. Bought with a known fault that both engines wont rev passed 2000 RPM with morse lever all the way ahead. Engines just get to about 70% and then there's no more. Previous engineer changed injectors, fuel pump, turbo chargers and boost sensors. They were using Jaltest to connect to the ECU but thought that the fuel pump rod was 100% WOT but we've had the local Volvo engineer down today and plugged in with Vodia to both engines and it showed max fuel rod position of 67% with morse lever full ahead. No fault codes shown so my thinking is that the EDC would call a fault if the fuel rod isn't where it should be or if the actuator wasnt moving the rod correctly ( codes 2.2 and 2.3). So the EDC thinks that the fuel rod should be where it is. Ive attached the picture of the scan. boost pressure seems normal at 185 KPA (27psi) for 1900 rpm. Interestingly relative load is at 100% with only 1912 rpm and 67% fuel rod position. EDC only restricts fuel on air inlet temperature (27 deg C) or boost pressure ( 27 psi) but both seem ok. Im thinking this is software related and that the EDC may need the software reloaded. Does anyone have any other ideas.

Interestingly at idle the EDC is calculating load at 81%. see attached JPG showing RPM at 592. At 100% load then does the EDC stop adding fuel?

 

[volvopaul]

Fairline phantom 43 with twin Tamd74P engines. Bought with a known fault that both engines wont rev passed 2000 RPM with morse lever all the way ahead. Engines just get to about 70% and then there's no more. Previous engineer changed injectors, fuel pump, turbo chargers and boost sensors. They were using Jaltest to connect to the ECU but thought that the fuel pump rod was 100% WOT but we've had the local Volvo engineer down today and plugged in with Vodia to both engines and it showed max fuel rod position of 67% with morse lever full ahead. No fault codes shown so my thinking is that the EDC would call a fault if the fuel rod isn't where it should be or if the actuator wasnt moving the rod correctly ( codes 2.2 and 2.3). So the EDC thinks that the fuel rod should be where it is. Ive attached the picture of the scan. boost pressure seems normal at 185 KPA (27psi) for 1900 rpm. Interestingly relative load is at 100% with only 1912 rpm and 67% fuel rod position. EDC only restricts fuel on air inlet temperature (27 deg C) or boost pressure ( 27 psi) but both seem ok. Im thinking this is software related and that the EDC may need the software reloaded. Does anyone have any other ideas.

Did you run without the sync button connected?
What are fault codes 2-2+2-3

 

[volvopaul]

Do have have comparable data from the sea trial for the other engine ?

 

[Alanarkison]

Do have have comparable data from the sea trial for the other engine ?

It's exactly the same Paul. Above readings were from the port engine. From the starboard, with morse lever full ahead, we got 166KPA (24psi) boost pressure, by the time we moved the laptop over to the starboard engine the temp in the engine room was 55 degrees C. Relative load showing 100% with the fuel rod again at 67%. RPM at 1944 As I understand from the manual the EDC looks at boost pressure and boost temp and then calculates load. More fuel is added as required dependant on morse position. But if the EDC is calculating 100% load then its my understanding that it won't add any more fuel as there would be no point and the extra fuel would be unburnt.

 

[Seastoke]

Are you based on the thames

 

[Alanarkison]

Are you based on the thames

No, West coast of Scotland

 

[volvopaul]

It's exactly the same Paul. Above readings were from the port engine. From the starboard, with morse lever full ahead, we got 166KPA (24psi) boost pressure, by the time we moved the laptop over to the starboard engine the temp in the engine room was 55 degrees C. Relative load showing 100% with the fuel rod again at 67%. RPM at 1944 As I understand from the manual the EDC looks at boost pressure and boost temp and then calculates load. More fuel is added as required dependant on morse position. But if the EDC is calculating 100% load then its my understanding that it won't add any more fuel as it there would be no point and the extra fuel would be unburnt.

You still haven’t answered my question, did you trial it with the sync button off which means it wasn’t lit blue, correct me if I’m wrong but identical data means you didn’t disconnect it . To me based on my years of diagnosis on edc motors you have a problem with just one engine which is holding back the other one because your running in sync mode.

 

[Seastoke]

I am no engineer , but it seems a common fault that something that controls both engines. When run individually is it the same.

 

[volvopaul]

It's exactly the same Paul. Above readings were from the port engine. From the starboard, with morse lever full ahead, we got 166KPA (24psi) boost pressure, by the time we moved the laptop over to the starboard engine the temp in the engine room was 55 degrees C. Relative load showing 100% with the fuel rod again at 67%. RPM at 1944 As I understand from the manual the EDC looks at boost pressure and boost temp and then calculates load. More fuel is added as required dependant on morse position. But if the EDC is calculating 100% load then it’s my understanding that it won't add any more fuel as there would be no point and the extra fuel would be unburnt.

Relative load will show full if the throttle is in the full position because it’s not meeting it’s rated speed, most edc engines show 100% until they can reach max rpm , was your man a Volvo guy ? Would have been better to use 2 vodias at the same time , save messing about , also did you carry out an acceleration test and test each engine again with sync off to read max rpm attained? Along with boost at certain rpm throughout the Rev range it will attain , I feel like your chasing around when it’s just the one motor that’s at fault , its highly unlikely you have a fault with both unless they draw fuel from the same tank in which I know they don’t unless you got the supply taps set wrong .

 

[Alanarkison]

Did you run without the sync button connected?
What are fault codes 2-2+2-3

yes with sync connected and disconnected. Still the same. According to the instruction manual page 103 EDC diagnostic Trouble Codes (DTC),
2.2 Control rod sensor Control rod position sensor transmits abnormal values to the control module
2.3 Control rod actuator Control rod actuator takes too much or little current. Open-circuit, connection 42. Main relay opens (engine stops).
Neither codes are showing in the DTC. In fact there are no error codes listed so the EDC must think that everything is working as should be.

 

[Alanarkison]

yes with sync connected and disconnected. Still the same. According to the instruction manual page 103 EDC diagnostic Trouble Codes (DTC),
2.2 Control rod sensor Control rod position sensor transmits abnormal values to the control module
2.3 Control rod actuator Control rod actuator takes too much or little current. Open-circuit, connection 42. Main relay opens (engine stops).
Neither codes are showing in the DTC. In fact there are no error codes listed so the EDC must think that everything is working as should be.

Previous two engineers ran with one engine off at a time and had reported the issue still remained.

 

[Alanarkison]

interesting post on Tamd74 EDC, high turbo pressure - Volvo Forums - Volvo Enthusiasts Forum
With a similar issue.

 

[Seastoke]

Have you disconnected the power to each engine then tried, as if you only have one engine , is it the same on the fly , I know f all just thinking.

 

[Alanarkison]

Relative load will show full if the throttle is in the full position because it’s not meeting it’s rated speed, most edc engines show 100% until they can reach max rpm , was your man a Volvo guy ? Would have been better to use 2 vodias at the same time , save messing about , also did you carry out an acceleration test and test each engine again with sync off to read max rpm attained? Along with boost at certain rpm throughout the Rev range it will attain , I feel like your chasing around when it’s just the one motor that’s at fault , its highly unlikely you have a fault with both unless they draw fuel from the same tank in which I know they don’t unless you got the supply taps set wrong .

Fuel crossover is closed so suction seperate. Engineer was a Volvo guy from DDZ marine Our local Volvo dealership. We didn't use two separate vodias but agree with sync off it would have made sense. we tested both engines at 25% morse, 50% morse and 100%. All gave fairly plausible boost readings, temps and engine rpms. what confuses me is that at idle in neutral the load shows 81%

 

[Alanarkison]

I am no engineer , but it seems a common fault that something that controls both engines. When run individually is it the same.

Agreed, I think I'm going to have the software reloaded first to rule it out as per the link to the post above on the Volvo enthusiasts page. I can't see this being the potentiometers in the morse station as there's two, flybridge and cabin and it does the same from both stations. Port EDC is common as its master and Starboard is slave. So starboard should match to port speed. Other than that boost pressure looks correct for 1900 rpm, 26 psi on port and 24 psi on starboard, all else looks ok.