Knock sensor

[rx7ben]

Hi guys
 
I need a little help. On the hand commander for  Apexi PFC ive noticed that the knock sensor has been moving up to about 1cm. Now ive never noticed it move at all ever before. The car has only done about 1500 miles on a Roetecnics rebuild. Should the Knock sensor be moving at all
 
 
Cheers

[shaunwil]

Has it been tuned or are you still running it in ?? The knock sensor is basically just a pickup looking for detonation. If there are other noises causing it to set off then it is possible to see higher figures.

Better off getting it on a dyno and see if there are any issues, the knock sensor isn\'t very good on the FD. I\'ve had readings off mine that says my engine would have melted by now !

Shaun

[rx7ben]

Has it been tuned or are you still running it in ?? The knock sensor is basically just a pickup looking for detonation. If there are other noises causing it to set off then it is possible to see higher figures.
 
Better off getting it on a dyno and see if there are any issues, the knock sensor isn\'t very good on the FD. I\'ve had readings off mine that says my engine would have melted by now !
 
Shaun

Yeah it has been tuned by David at roetenics. Thinking about it ive probaley done about 3000 miles so it run in proper.

[DMDRIFTING]

My knock sensor is hitting 140 on slow gradual acceleration under 3.5k???

On full chat from 4.5k to redline it won\'t go higher than 34!


After researching on here, it seems the sensor is very sensitive to all noises as well as knock, 140+ should destroy the engine? But the fact that WOT full load and boost returns a reading of 34  it  would seem that, it is as it should be, and nothing to worry about?

Can anybody confirm this?

[Nik da Greek]

Mine does the same, I think it peaks at around 170 on an average drive, which is clearly nonsense. I just ignore it and let it do its own thing, the cars not blown up yet!

[DMDRIFTING]

How long has yours been returning knock values like this Nik?

I wonder is there a way to fix the sensitivity?

[Nik da Greek]

Dunno! It\'s been doing it ever since the Apexi Power FC was fitted, possibly before, but obviously there was no way of telling before. There was a whole raft of running problems on it at the time, so I basically ran out of patience, money and humour before I got round to replacing the knock sensor, which is what malfunctions to cause this ridiculous reading IIRC.

It\'s something that should be sorted really, because it means you clearly cant tell what the knock really is, but I gather its quite a pig. I had to get the values adjusted on the Power FC, too to stop it from flashing the engine heat light all the time as a warning, but I couldn\'t tell you how this was done because the tuner did it for me and I was sulking by then so didnt pay enough attention! :Giggle

[shaunwil]

I think sometimes a fixed used is to glue the sensor in place. Only way to cure it is to find what is giving off the false vibration which is not at all easy !

Shaun

[DMDRIFTING]

Are you pulling my leg, glue?? :Giggle


I can imagine the theory but!

[gandyRX]

140!!!! imo thats very high, before mine was mapped it used to reach 40, that was running lean, now it doesent really go above 26 on on boost and hardly goes above 3 on idle, but i was talking to carl a while back and he said some fd\'s run 200, the knock sensor is basicaly a microphone thats listens to the detonation in the engine and other things can set it off too

[DMDRIFTING]

Its annoying

[Timmy]

I had a gap in my map where it would knock at low revs under heavy load. Than again it could be something is simply rattleing in the engine bad. We could always just drive round wearing det cans.

[DMDRIFTING]

Love it! :rollin

[shaunwil]

Are you pulling my leg, glue?? :Giggle
I can imagine the theory but!

From what I\'m aware some tuners superglue the sensor to the block to get a better cleaner signal. I\'m not pulling you leg !

Shaun

[DMDRIFTING]

Ok superb,

time to remove, clean and add a touch of glue to the knock sensor when fitting!

Cheers