Volvo KAD 300 Supercharger

[frenzy]

Hi All

I have twin Volvo Kad300s. the port engine goes fine up to approx 1800 revs but then will struggle to go any more.The starboard is fine. Then it sudden picks up power again an d it’s fine.
Just wondering is it the supercharger clutch ? I have checked the fuse and belt and all are fine.

 

[DavidJ]

Comparing the noise with the starboard engine can you hear the supercharger cut in at 1800 not under load.

 

[kashurst]

The supercharger on a KAD 300 starts at 1000 rpm and drops out at 2800rpm.
As the problem is erratic and your supercharger seems to be kicking in as you can get to 1800 rpm, I would check out the fuel system. Sounds like a partially blocked fuel filter/component somewhere,

 

[DavidJ]

In light of kashurst information I’ll modify my question. (My world is KAD43) Can you hear or see the supercharger cut in at 1000 or thereabouts. Any fault codes?

 

[frenzy]

Just stated the engine and I do not hear the supercharger kicking in

 

[kashurst]

if the engine is stone cold the super charger will start immediately regardless of revs
if the engine is sufficiently warm when you start it, the supercharger will only kick in over 1000 rpm+

If you have a resistance/multimeter, measure the resistance of the coil in the supercharger clutch. It should be about 4 ohms. If its zero or 100K+ its gone.

 

[frenzy]

Tested the circuit it’s approx 5oh. Where should I test next

 

[Portofino]

I would look @ the turbo , the bearings could be fried .This is factor of oil quality and change Fq which you have not alluded to .
Age and overloading , burns the tips of the blades off so they loose efficiency.
Then the housing is made of metal that corrodes in a marine environment, so internally they corrode and the gap increases , = less boost .
All assuming the SC clutch is serviceable and the thing itself has been regularly oil level checked and changed etc .
Normal SC range is 1400 to 2800 rpm .

 

[frenzy]

Replaced the Turbo last season. So I would hope that it should be ok. Is it possible that the super charger clutch is failing as when I go above 2000 revs the power comes back after a few seconds delay. It’s when I hit 1800 revs that it’s seems to have the problem .

 

[kashurst]

Check that the supercharger clutch centre is rotating really fast when the engine is over 1000 rpm - compare it to the other engine. If the clutch is not being operated the centre section with the 3 metal strips will only rotate fairly slowly.

Check your fault codes
Check continuity in the engine harness right back to the ECU connector
Disconnect the ECU connector and other connectors apart and spray with proper contact cleaner and refit it a few times (be gentle with it)
Check the air filter - unlikely but never assume
Check your fuel system - have a look inside the fuel shut off valve and the racor/volvo style filters for debris.
Check there is good flow from the shut off valve into a clean container
Take the filter assembly apart and check all the passageways are clear. Take the silver ball (its a none return valve) out and don't put it back in. Put it all back together bleed it etc.

If you still have a problem swap the ECUs over and try that.

 

[volvopaul]

Hi All

I have twin Volvo Kad300s. the port engine goes fine up to approx 1800 revs but then will struggle to go any more.The starboard is fine. Then it sudden picks up power again an d it’s fine.
Just wondering is it the supercharger clutch ? I have checked the fuse and belt and all are fine.

Boost pressure switch

 

[frenzy]

Thanks Paul.

with regards to the boost pressure switch, is that the one in the ECU and is it easy to change for an amateur ?

 

[volvopaul]

Thanks Paul.

with regards to the boost pressure switch, is that the one in the ECU and is it easy to change for an amateur ?

Yes and yes

 

[frenzy]

Ok. Change the boost pressure switch. Brought the boat for spin and no change .Port engine goes to 1800 and then struggles. Bring the starbord engine to 2200 and eventually it seems to carry it up to speed. Then both engines run fine from there. Opened the hatch as I drove and the port enginine sounds the same all the way through the revs as though the supercharger is not kicking in. The starboard whines when the supercharger kicks in.

 

[kashurst]

have you done everything in post #10 ?

 

[frenzy]

Could not check the supercharger clutch as I was driving on my own but from what Im hearing it’s not kicking in. With regards the clutch, would the fuse blow if it was failing or could it just kick in and out. That clutch was replaced 2 years ago. Checked the racor filter and that seemed fine. No fault codes showing. Checking the continuity may be beyond me, so might get someone who knows.

 

[frenzy]

With regards to swapping the ECU, does the connection with the wires. Just unplug as I could not move them when I was changing the sensor.

 

[BruceK]

Not sure if the KAD 300 uses the same pickup rev sensor as the early KADs do to determine revs for SC engagement but it may be worthwhile swapping them over to check if the sensor is OK if swapping ECU doesn't highlight any issues.

 

[kashurst]

With regards to swapping the ECU, does the connection with the wires. Just unplug as I could not move them when I was changing the sensor.

send me a PM with an email address and I will send you the manuals. The ECU connector has a red lock device you need to release first. (I think you slide the red part down ) Be careful with all the connectors its easy to damage something.

 

[volvopaul]

Not sure if the KAD 300 uses the same pickup rev sensor as the early KADs do to determine revs for SC engagement but it may be worthwhile swapping them over to check if the sensor is OK if swapping ECU doesn't highlight any issues.

No all done in a highly sophisticated way through the ecu