KAD 300 over-revving problem

[HectorP]

I have a Sealine with twin Penta KAD300 engines. Both have been recently serviced and <500Hrs. The starboard engine, after running for a while, and then revved slightly accelerates to around 1800 rpm and will not return to idle and has to be stopped. The problem starts after about 30 minutes idle running but has also occured at sea. On restart the engine idles normally until the next time the revs are increased, when the problem recurs immediately. The engineers have so far failed to find a simple reason or a solution.

Any thoughts?

 

[kashurst]

check ALL the engine and control electrical connections - pull apart and spray with contact cleaner, check for anything iffy
re-calibrate the throttles.

 

[QBhoy]

Might be time to check the injectors

 

[HectorP]

check ALL the engine and control electrical connections - pull apart and spray with contact cleaner, check for anything iffy
re-calibrate the throttles.

Many thanks for reply
Engineers did that and followed with a successful sea trial, but problem recurred the next time the engines were run! Throttle unit has been tested and is OK.

 

[HectorP]

Might be time to check the injectors

Many thanks for the reply.
There was a faulty injector, but it’s been replaced.

 

[A_8]

Maybe the kompressor control fails i.e it cuts in when it should not.

 

[oldgit]

check ALL the engine and control electrical connections - pull apart and spray with contact cleaner, check for anything iffy
re-calibrate the throttles.

Proper switch cleaner such as Servisol 10 , not WD40 or similar !

 

[volvopaul]

I have a Sealine with twin Penta KAD300 engines. Both have been recently serviced and <500Hrs. The starboard engine, after running for a while, and then revved slightly accelerates to around 1800 rpm and will not return to idle and has to be stopped. The problem starts after about 30 minutes idle running but has also occured at sea. On restart the engine idles normally until the next time the revs are increased, when the problem recurs immediately. The engineers have so far failed to find a simple reason or a solution.

Any thoughts?

Are you sure it’s 1800 and that your rev counter is correct ?
reason I ask is that the engine goes into limp mode if an edc component fails , limp mode is a get you home feature .

when you stop the engine this cancels the fault , anything like a faulty plug to each edc sensor can cause the engine to go to limp .

next time it occurs press the D Diagnosis button and read the flash code before you stop it .

 

[HectorP]

Are you sure it’s 1800 and that your rev counter is correct ?
reason I ask is that the engine goes into limp mode if an edc component fails , limp mode is a get you home feature .

when you stop the engine this cancels the fault , anything like a faulty plug to each edc sensor can cause the engine to go to limp .

next time it occurs press the D Diagnosis button and read the flash code before you stop it .

Thanks for this
I’ll check for a flash code next time
It may not be exactly 1800 and it floats a bit in the range 1700-2000 rpm

 

[HectorP]

Maybe the kompressor control fails i.e it cuts in when it should not.

Thanks for that thought. I’ll try to get the compressor control card tested

 

[petem]

Does it smoke?

Has your mechanic tried plugging in Vodia to read any historic fault codes?

 

[HectorP]

No, no smoke
I can’t answer about the Vodia since they are closed for COVID-19, but they are Volvo engineers. They suggested that if contact cleaning didn’t work (which it appeared to initially) that the ECU may need to replaced!

 

[kashurst]

before you drop for an new ECU, swap them over and see if the fault moves to the other engine.

 

[HectorP]

before you drop for an new ECU, swap them over and see if the fault moves to the other engine.

Yes, thanks. Makes complete sense and I will certainly do that.