Knock sensor doesn't work, help please.

[disco stu]

I suspected that my knock sensor wasn'r working, so I tested it w/ an extension and hammer and I was right. So i replaced it and still nothing. What gives.

It was working before the recent rebuild.

Checked to see if the wire got pinched against the firewall, doesnt look like it.

Does the sensor go to the ESC or the ECM?

Knock count and knock retard on DS do not change.

And no codes.

SO, where would you guys start looking?

 

[striker_29]

I would check the esc. It controls knock readings and may be your problem. I would say try and borrow one though, cause last time I checked they had gotten really expensive for some reason. If worse comes to worse check Caspers. Good luck

 

[disco stu]

Thanks, I was afraid of that.

 

[disco stu]

OK, got knock counts but no knock retard. Knock sensor torqued to 16 ft lbs. I can bang on the block pretty good and nada. Don't get it. It used to go crazy the last time I did this.

 

[disco stu]

ttt

 

[U1ARUNIT]

This is just a S.W.A.G. but... If you are getting knock counts but no retard, (are you are trying this at idle??) and the ECM is setup to only retard the timing when the engine is over a certain RPM..? That sentence is confusing to me even and I wrote it..

Try holding it at 2500 RPMS when you tap and see what ya get. The car should drop down a little in RPMS or stumble a little when the area next to the sensor is tapped with a long extention and a hammer. Try this and get back..

 

[TurboDave]

Originally posted by disco stu
OK, got knock counts but no knock retard. Knock sensor torqued to 16 ft lbs. I can bang on the block pretty good and nada. Don't get it. It used to go crazy the last time I did this.

You're over torqued. Back it out and re-torque to 14 ft lbs.

You may or may not see knock retard. It all depends on the frequency and duration of the knock counts.

Sounds like it's working, you just need to get the torque set properly.

Threads don't have anything on them, do they?

 

[U1ARUNIT]

Dave,

From the factory they come with a red coating on them. Not sure but it's probably loc-tite or the like. The difference between his torque and the reccomended torque will make little(actually I say ZERO) difference to what he is talking about.

You can probably count on one hand the guys on this board who actually use a torque wrench to tighten theirs, and how much ya wanna bet that even if they do their wrench wouldn't be calibrated enough to be THAT (within 2 ft/lbs) accurate anyways.

 

[disco stu]

Originally posted by U1ARUNIT
Try holding it at 2500 RPMS when you tap and see what ya get. The car should drop down a little in RPMS or stumble a little when the area next to the sensor is tapped with a long extention and a hammer. Try this and get back..

Thanks alot, I didn't even think of that. Did some bangin and, and pow! 14.7 deg. Better to err on the safe side, hence my concern for the correct operation of this sensor. . I forgot that my Extender has the false knock ignore feature, so I swapped in an old CPP mini mag and tached it up and everything works fine (Except maybe the operator)

Many thanks.