Knock sensor

Stempy · Post by **Stempy** » 08 Jun 2004, 01:56

Anyone know what the resistance reading of this unit should be?

ItDontGo · Post by **ItDontGo** » 08 Jun 2004, 01:59

It wont really have a resistance reading. Its a piezo-electric device like in those annoying musical birthday cards. I would not know how to test one.

Stempy · Post by **Stempy** » 08 Jun 2004, 02:11

Probably why it reads in the mega ohms region then.

AndersDK · Post by **AndersDK** » 08 Jun 2004, 02:18

It would produce (ac) voltage on mechanical knocking, i.e. holding the sensor against the body of an air impact socket driver.

xantiav6 · Post by **xantiav6** » 08 Jun 2004, 02:50

I think the way to test a knock sensor is to run the engine with a timing light attached, then tap the sensor with a screwdriver and watch the timing jump back.
I don't think this is a likely cause of a misfire.
regards,
Mike

Stempy · Post by **Stempy** » 08 Jun 2004, 02:58

Probably not the cause of a misfire as you say, but just wondered what it should read. I think I might try the crank speed sensor first.