Could this be a Ecu sensor?

[Portland Billy]

On a trip back from IOW last year my port engine suddenly dropped to 2500 revs and would do no more.
We went through a bit of bad weather, but despite the choppy conditions the revs were steady, and remained so for the rest of the trip back to Thames.
First thoughts were fuel filters and these have been changed, but I haven't been outside the tidal Thames this year so unable to test.
Reading recent thread on Motor Boat forum makes me think it could be an Ecu sensor issue.
Any thoughts?

 

[Parabordi]

could be, mine have error codes and once you have hit ten errors it would go into limp home mode.
then you have to clear the errors to get back to normal.
..so I bought the kit for that.

 

[Chris_d]

What engine is it?

 

[Portland Billy]

KAD 44

 

[Chris_d]

KAD 44

Boost sensor possibly, Petem on MoboChat has KAD44's and had a similar issue but Volvopaul is the man. You should be able to read a fault code by the number of flashes on the EDC display which might help.

 

[oldgit]

Possibly supercharger not being engaged, duff clutch/relay
Know one skipper ran around for ages with a supercharger not working due to faulty clutch.
Boat was a Prestige 36 with pair of KADs.

 

[Chris_d]

Possibly supercharger not being engaged, duff clutch/relay
Know one skipper ran around for ages with a supercharger not working due to faulty clutch.
Boat was a Prestige 36 with pair of KADs.

Yes approx 2500/2800rpm is where the supercharger is supposed to cut out and the Turbo take over, hence if boost sensor fails it thinks the Turbo is bust so defaults to safe mode. Boost sensor is in the ECU and fairly easily changed I understand, but best to get a positive diagnosis first.

 

[Portland Billy]

Many thanks to all for the input, which confirms my uninformed original diagnosis!
Next step is probably DB marine and £s.
Unless anyone knows of someone cheaper and reliable.

 

[Chris_d]

Have a word with VovlPaul on the mobo forum he does come out to the Thames I think but can probably diagnose it first before you spend ££

 

[oldgit]

Will ask the chap with the Prestige how he got it fixed.
Not sure if he got somebody in or swapped something out himself.

 

[Chris_d]

Will ask the chap with the Prestige how he got it fixed.
Not sure if he got somebody in or swapped something out himself.

He needs to get a definite diagnosis first, as it dropped to 2500rpm that suggests nothing to do with the supercharger or clutch as that would already be disengaged, if it wouldn't accelerate past 2500rpm then that can be supercharger clutch, but the sudden drop suggests a sensor is more likely.