Strange goings on with one of my KAD43's

[DavidJ]

Strange goings on with one of my KAD43\'s

When setting off from cold my s'board throttle lever position is noticably behind that of the port lever to achieve the same rpm. I stay at this position at 2500 rpm and when the temperature guage hits 85 deg C, the s'board engine instantly looses 500 rpm, I compensate by moving the s'board lever forward and the levers are level and all is well.
Whats going on here, The port engine doesn't go through this performance.
The boat is a S37 with twin KAD 43's
David

<hr width=100% size=1>

 

[hlb]

Re: Strange goings on with one of my KAD43\'s

More likely the rev counters playing up. I have a port upsairs one that does it now and then.

<hr width=100% size=1> <font color=blue>No one can force me to come here.<font color=red> I'm a volunteer!!.<font color=blue>

Haydn

 

[Moose]

Re: Strange goings on with one of my KAD43\'s

Well surely he would be going round in circles then! If the Gauges are wrong and you would be getting an awful vibration.

<hr width=100% size=1>

Moose

 

[BarryH]

Re: Strange goings on with one of my KAD43\'s

Do you listen to your engines or rely on the tachos. Get into the habit of listening to the engine note. You'll soon see whats better. Your ear or your tachos.

<hr width=100% size=1>

 

[hlb]

Re: Strange goings on with one of my KAD43\'s

Would E eck. E's only talking about 500 revs. On two boats I've never seen rev counters correct. You can tell when you have four of them. Even more when you get a tester on them. I Fink he just thinks the engines are running at different revs!!

<hr width=100% size=1> <font color=blue>No one can force me to come here.<font color=red> I'm a volunteer!!.<font color=blue>

Haydn

 

[hlb]

Re: Strange goings on with one of my KAD43\'s

Have you ever tried to listen to two engines at once??

<hr width=100% size=1> <font color=blue>No one can force me to come here.<font color=red> I'm a volunteer!!.<font color=blue>

Haydn

 

[BarryH]

Re: Strange goings on with one of my KAD43\'s

Yes, you get the feel for them. The things on the dash are called gauges for a reason.

<hr width=100% size=1>

 

[DavidJ]

Re: Strange goings on with one of my KAD43\'s

Definately not the rev counter, you can hear the engine note drop and the pull as power is lost.
David

<hr width=100% size=1>

 

[hlb]

Re: Strange goings on with one of my KAD43\'s

You said nothing about power beig lost. Only that you had increased power. You wi ll always get one tmperature sooner than other depending which is running Califier. Check Fuel fillters in duff engine, First.

<hr width=100% size=1> <font color=blue>No one can force me to come here.<font color=red> I'm a volunteer!!.<font color=blue>

Haydn

 

[DavidJ]

Re: Strange goings on with one of my KAD43\'s

When up to temperature the engines go like a bomb so not likely to be fuel filter. The stange 'happening' feels like a sensor kicking in at 85 C which immediately reduces the engine rpm and in consequence I have to increase the throttle to compensate. But it only happens on one engine.
Are the turbo's triggered by temperature?? I didn't think so??
David

<hr width=100% size=1>

 

[hlb]

Re: Strange goings on with one of my KAD43\'s

Well I'm lost then.

<hr width=100% size=1> <font color=blue>No one can force me to come here.<font color=red> I'm a volunteer!!.<font color=blue>

Haydn

 

[longjohnsilver]

Re: I\'m lost

Nothing unusual there then, have you found your way back to Plymouth yet??

Or are you now the Marie Celeste of the English Channel? /forums/images/icons/wink.gif

<hr width=100% size=1>

 

[hlb]

Re: I\'m lost

Wot you mean I took you to places that did not even exist till we got there. Especialy that bit of sea about 3 miles off Falmouth! Dont think anyones been there before. If they have I cant think why!!........./forums/images/icons/laugh.gif

<hr width=100% size=1> <font color=blue>No one can force me to come here.<font color=red> I'm a volunteer!!.<font color=blue>

Haydn

 

[Chris_B4]

Re: Strange goings on with one of my KAD43\'s

I have Mercruisers so don't really know about Volvos but I suspect they are electrocnically managed in much the same way.

I wonder if it's a fault with the engine management system or a temperature sensor somewhere. You would expect the engine management to run a different set of parameters until the engine reaches normal operating temperature, bit like the equivalent of a choke. Maybe its not getting a clear signal from the temperature sensor until it hits 85c so instead of altering gradually it switches suddenly.

Just guessing really


<hr width=100% size=1>

 

[DavidJ]

Re: Strange goings on with one of my KAD43\'s

Good point Chris. Certainly makes sence. I'll have a poke around to see if there is anything obvious then either ignor it or throw some money at Volvo to fix it.
thanks
David

<hr width=100% size=1>

 

[Chris_B4]

Re: Strange goings on with one of my KAD43\'s

David

Sorry to resurrect an old thread but did you get to the bottom of this, I'm curious

Chris

<hr width=100% size=1>

 

[Duncan_Hamble]

Re: Strange goings on with one of my KAD43\'s

David,

The superchargers are "switched" in and out by electromagnetic clutches and could cause this phenomenon say if one is switched in early the engine would get extra power. On the other hand note that the belt that drives the supercharger also drives the alternator which sends the signal to the tacho. Often these belts slip, especially just as the supercharger is switched in causing the tacho to under read for a while.

You can tell if the supercharger is running by looking at its pulley - compare your two engines.

Also have a look at the belt condition - they may need changing and in any case seldom last as long as VP reckon they should.

IHTH

Duncan

<hr width=100% size=1>