Tohatsu 40d2z nearly rythmic buzzing noise on idle

[380voltz]

Hi ye all ....

My 2006 engine is making a nearly rythmic noise on idle. When this happens the engine stutters and the idle gets unstable, then the buzzing stops and the idle stabilizes again.
the buzzing sound is coming from the flywheel area.
wierd symptom. any clues pls ?

hope ur all enjoying summer

cheers

 

[380voltz]

Re: Tohatsu 40d2z nearly rythmic buzzing noise on idle

bump ....

 

[TOHATSU GURU]

Re: Tohatsu 40d2z nearly rythmic buzzing noise on idle

Could be a trigger coil leaking to ground. Try running the ignition diagnostic tests.

 

[380voltz]

Re: Tohatsu 40d2z nearly rythmic buzzing noise on idle

So i Ran thru the ignition test procedure and these are my results

Exiter

test 1 = 520 ohm = ok
test 2 = no resitance to grnd = ok
test 3 = 11v & 0.5v to engine grnd respectivly = not ok
test 4 = 137v between orange cable and w/grn = ok


Pulser coils

test 1 resistance 220ohm on each coil = ok
test 2 220ohm to engine grnd on each coil = not ok
test 3 there is some voltage to grnd on all three pulser = not ok
test 4 coil grnd to wire 6,8,10 = abt 0.15v = not ok

so if my reading are right, both my exiter and pulser coils are fried ?? how is this possible?
the engine is running, apart from the buzzing sound and the rough idle it seems fine ?

pls advise

cheers

 

[TOHATSU GURU]

Re: Tohatsu 40d2z nearly rythmic buzzing noise on idle

If you used a digital meter, the readings are incorrect. If you used an analog meter, did the testts correctly and the values are outside of what the factory service manual calls for...Then you have multiple component failures.

 

[380voltz]

Re: Tohatsu 40d2z nearly rythmic buzzing noise on idle

Cheers for speedy response. I actually did use a digi meter and set DVA in ac mode. if I may ask, why wldnt this work pls? is it to do with damping?