The Knock Sensor in B230F in Volvo 740 ?

Hallow
How I can I tested this sensor? I think that can be he damaged. The engine
works ok, there are with him no problems, but meseems that the acceleration
is too poor, compered to other Volvo 740. I heard that such symptoms could
give the damaged this sensor. How can I check, that he works ok or not?

Thanks for all...

 

Basically it is a microphone. You could tap it whilst monitoring it on an
oscilloscope (there are a few small handheld ones that will do nicely). Just
check the connections (beware, screened cable) or try tapping it when engine
is running and see if engine exhibits changes in response to tapping.

All the best, Peter.

700/900/90 Register Keeper,
Volvo Owners Club (UK).

 

If you connect it to an oscilloscope and tap on it with a screwdriver or
something you should see voltage spikes. They don't often fail though
unless they physically break.

 

Tnx so much. I haven't got any oscylloscop,so it is a problem I've got
only simple multimetr, I can test for example a resistance ?

How strongly I've to tap the Knock Sensor, when engine is running??
And what will be symptoms of the engine during the tapping??

I want to deinstall this sensor, to clean up him and his place in the
engine, and again install him - What power I must to use to screw on him (in
Nm ??) ?

What other sensors are accountable for the ignition, except the knock
sensor? Can I the ignition setting by hand (I have LH 2.2)? if yes, where is
the mark to setting the ignition by stroboscope lamp??

All the best...

 

If you set the multimeter to measure AC volts and then tap on it you
might see small pulses, at least if the meter has an analog bargraph, or
perhaps connect it to an audio amplifier and see if tapping on it
produces a sound from the speakers. Alternatively you could just swap it
with a used one from a junkyard.