Volvo KAD 300 sporadic limp mode ?

[-Chris-]

Looking for help and ideas... KAD300 in 275 Amberjack @ 1000 hours -based in New Zealand. I am experiencing random sporadic limp mode shutdowns that only last 3 to 5 power ups after checking all clear in bilge...then boat will run happily for an hour cruising. Usually this occurs 1 to 2 k out from marina motoring at 20knot cruise, boat will auto reduce revs to 1000rpm and continue at idle speed... will go back into neutral and power up 3 to 5 times each time getting to approx 3000 -3200 rpm before falling back into limp. On next attempt to power up boat will pull up onto plane and run at 20 to 22 knots for easily an hour with no issues... after fishing for an hour the boat will start / get up on plane for 1 to 2 k and then bang into limp mode again 3 to 5 times.. then power up and run home without hesitation. The last run out from marina the boat cruised for an hour before falling into limp mode.. again took 3 to 4 false starts before getting up on plane and cruising home.. video of this is shared on google drive link below if it helps to watch? Boat is fully serviced and maintained regularly. New racor and diesel filters with fuel line checked right back to tank including pickup in tank and fuel tested clean ( fuel bowl on racor clean) Installed a new turbo when head was rebuilt after a gasket leak cracked a valve @ 800 hours, Supercharger is running exactly as expected - starts and runs on warm up.. cuts out when hitting 2700-2800 rpm, New air filter. Have replaced speed sensor and potentiometer as thought it was causing a no start issue( no green on edc dash panel /turned out be loose terminal in wiring loom over oil filters) Have tested all sensors/ relays with multimeter and all showing correct numbers. Have checked the tubes to the boost sensor and clear and no sign of condensation.
I had tried pulling the cable off the stop solenoid on injector pump after going into limp mode and boat started up but ran really rough as if being starved of fuel, given this solenoid needs to be powered up to stop flow I assume there should be no reaction from motor when disconnected?... am I wrong with this thought?... next step will be pull that solenoid and check the spring holding the plunger up as maybe an issue ?
Will try disconnecting/bypassing the Seafire unit and run it and see if that makes any difference as seems that folks on here have had issues with that unit!
Anyone have had similar issue or ideas where to look next? Seems unusual that it enters limp mode then will allow me to power up to 3000rpm several times then power up and run at speed for an hour.... once or twice the boat has surged several times after dropping back into limp without touching throttle as if a loose connection is causing issue! This issue has been occurring for around 6 months but boat will always keep running to get me home.. never actually shut down fully!
All and any help appreciated
Local volvo techs have been no real help with these issues unfortunately as being sporadic its really hard to pin down!
ps I know enough about the motor to be dangerous but did find the wiring issue which volvo techs gave up on!
Link to video showing stop and start issue - KAD300 limp mode – Google Drive

 

[kashurst]

Sounds like an intermittent electrical connection issue. The ECU can't sense the injection pump reliably
check the round connector and wiring from the injection pump to the ECU. Clean and spray with a decent contact cleaner and connect/disconnect a few times
Do the same with the main ECU connector - make sure you take it off as per the manual. They are getting old and brittle so you don't want to damage it.

Hopefully that will sort it, but it might take a few repeats.

 

[oldgit]

Sounds like an intermittent electrical connection issue. The ECU can't sense the injection pump reliably
check the round connector and wiring from the injection pump to the ECU. Clean and spray with a decent contact cleaner and connect/disconnect a few times
Do the same with the main ECU connector - make sure you take it off as per the manual. They are getting old and brittle so you don't want to damage it.

Hopefully that will sort it, but it might take a few repeats.

and Chris ....not WD40 or similar ...............vital proper electrical switch cleaner .

 

[petem]

Looking for help and ideas... KAD300 in 275 Amberjack @ 1000 hours -based in New Zealand. I am experiencing random sporadic limp mode shutdowns that only last 3 to 5 power ups after checking all clear in bilge...then boat will run happily for an hour cruising. Usually this occurs 1 to 2 k out from marina motoring at 20knot cruise, boat will auto reduce revs to 1000rpm and continue at idle speed... will go back into neutral and power up 3 to 5 times each time getting to approx 3000 -3200 rpm before falling back into limp. On next attempt to power up boat will pull up onto plane and run at 20 to 22 knots for easily an hour with no issues... after fishing for an hour the boat will start / get up on plane for 1 to 2 k and then bang into limp mode again 3 to 5 times.. then power up and run home without hesitation. The last run out from marina the boat cruised for an hour before falling into limp mode.. again took 3 to 4 false starts before getting up on plane and cruising home.. video of this is shared on google drive link below if it helps to watch? Boat is fully serviced and maintained regularly. New racor and diesel filters with fuel line checked right back to tank including pickup in tank and fuel tested clean ( fuel bowl on racor clean) Installed a new turbo when head was rebuilt after a gasket leak cracked a valve @ 800 hours, Supercharger is running exactly as expected - starts and runs on warm up.. cuts out when hitting 2700-2800 rpm, New air filter. Have replaced speed sensor and potentiometer as thought it was causing a no start issue( no green on edc dash panel /turned out be loose terminal in wiring loom over oil filters) Have tested all sensors/ relays with multimeter and all showing correct numbers. Have checked the tubes to the boost sensor and clear and no sign of condensation.
I had tried pulling the cable off the stop solenoid on injector pump after going into limp mode and boat started up but ran really rough as if being starved of fuel, given this solenoid needs to be powered up to stop flow I assume there should be no reaction from motor when disconnected?... am I wrong with this thought?... next step will be pull that solenoid and check the spring holding the plunger up as maybe an issue ?
Will try disconnecting/bypassing the Seafire unit and run it and see if that makes any difference as seems that folks on here have had issues with that unit!
Anyone have had similar issue or ideas where to look next? Seems unusual that it enters limp mode then will allow me to power up to 3000rpm several times then power up and run at speed for an hour.... once or twice the boat has surged several times after dropping back into limp without touching throttle as if a loose connection is causing issue! This issue has been occurring for around 6 months but boat will always keep running to get me home.. never actually shut down fully!
All and any help appreciated
Local volvo techs have been no real help with these issues unfortunately as being sporadic its really hard to pin down!
ps I know enough about the motor to be dangerous but did find the wiring issue which volvo techs gave up on!
Link to video showing stop and start issue - KAD300 limp mode – Google Drive

Have you checked for diagnostic codes when it's happened?

 

[volvopaul]

If it’s in limp you will have codes and 1200 rpm .
Sounds like the stop solenoid sprung has gone weak which allows the stop plunger to drop restricting the fuel flow to the cam plate head .

 

[-Chris-]

Sounds like an intermittent electrical connection issue. The ECU can't sense the injection pump reliably
check the round connector and wiring from the injection pump to the ECU. Clean and spray with a decent contact cleaner and connect/disconnect a few times
Do the same with the main ECU connector - make sure you take it off as per the manual. They are getting old and brittle so you don't want to damage it.

Hopefully that will sort it, but it might take a few repeats.

Thank you for your input! I have had the connectors apart a number of times while checking electrical but will definitely give them a thorough cleanup and maybe open the male contact terminals a little to ensure a good connection! thanks for your response!

 

[-Chris-]

Have you checked for diagnostic codes when it's happened?

checked for codes on edc and getting 1 -1 code clear everytime this occurs! thanks

 

[-Chris-]

If it’s in limp you will have codes and 1200 rpm .
Sounds like the stop solenoid sprung has gone weak which allows the stop plunger to drop restricting the fuel flow to the cam plate head .

Thanks.. have never had diagnostic codes but odd that the boat will drop to low revs while throttle still in 20 knot position but then will power back up to 3000rpm after going back to neutral only to limp again several times before fully powering up onto plane! The stop solenoid was next to come out but just waiting on Ovlov (local volvo dealer down under) to reopen after a long weekend to order new spring if available! I was puzzled that when I disconnected the stop solenoid after a drop in power that the boat accelerated back onto plane but ran really rough as if a fuel starve... as there should be no change to the solenoid unless powered on ?

 

[-Chris-]

Got to say a special thanks to VolvoPaul! ... He had mentioned the issue with kad300 injector pump stop solenoid spring in another post ages ago and again in response to the issue I was having. Updated... while on back order for a replacement stop solenoid spring I simply removed the old spring and stretched it before reinstalling.. Hey presto ... first time in 6 months I motored a two hour round trip without a hiccup! ... Now installed the new spring and again today motored for around 4 hours without an issue!... Fingers crossed the sporadic limp mode issue is resolved! Thanks to all for helpful response!

 

[kashurst]

Excellent. Thanks for posting the conclusion

 

[volvopaul]

Got to say a special thanks to VolvoPaul! ... He had mentioned the issue with kad300 injector pump stop solenoid spring in another post ages ago and again in response to the issue I was having. Updated... while on back order for a replacement stop solenoid spring I simply removed the old spring and stretched it before reinstalling.. Hey presto ... first time in 6 months I motored a two hour round trip without a hiccup! ... Now installed the new spring and again today motored for around 4 hours without an issue!... Fingers crossed the sporadic limp mode issue is resolved! Thanks to all for helpful response!

Great result , and thanks for letting us all know .