View Full Version : Knock sensor?
Guys what is the job of the knock sensor and what does it do?
Damo.
knock knock? who's there? hahahahah
em iirc it detects detonation (pinking) and send a signal to the ecu to sort it out,,,, i think
knock knock? who's there? hahahahah
em iirc it detects detonation (pinking) and send a signal to the ecu to sort it out,,,, i think
Ok so as i said in my other threads i wonder if this could be the cause of my problem with my ecu light coming on at around 3000-3500rpm?
As when it comes on it sounds and is very low on power.
on the cavi ecorec engines when the em light cam on the engine went into a get me home safe mode so that could explain the loss of power, if you have pinking get the co's checked by a propper dude with an egghead and a computer, i done that with my e16se ( which doesnt have a knock sensor ) which was pinking badly on low down revs, he ran a couple of tests fixes an earth problem and set the co and the difference was fantastic.
on the cavi ecorec engines when the em light cam on the engine went into a get me home safe mode so that could explain the loss of power, if you have pinking get the co's checked by a propper dude with an egghead and a computer, i done that with my e16se ( which doesnt have a knock sensor ) which was pinking badly on low down revs, he ran a couple of tests fixes an earth problem and set the co and the difference was fantastic.
Yea mate i flashed the codes off the ecu and i got:
1. knock sensor 1: no change in voltage.
2. AFM: Low voltage.
3. Oxygen sensor : no change in voltage.
But ive fitted new AFM an oxygen sensors but the codes may still be on the ecu even though ive unplugged it lol.
im afraid my knowlage is short when it comes to fixing problems lol i like working out what the problem is then if i CBA fixing it i give it to a man in a garage to fix lol, ecu's are beyond me mate, hopefully someone else will be along shortly to help:thumb:
im afraid my knowlage is short when it comes to fixing problems lol i like working out what the problem is then if i CBA fixing it i give it to a man in a garage to fix lol, ecu's are beyond me mate, hopefully someone else will be along shortly to help:thumb:
Cheers bazil + rep for your help anyway.
craig green
06-03-10, 10:14 PM
If the knock sensor & ICV plugs are incorrectly wired (common) you get those faults. + a bad idle as the signal for the ICV will be going to the knock sensor.
The knock sensor detects the detonation & the ECU uses this to retard the timing until det stops.
NitrousVaux
06-03-10, 10:17 PM
Yea mate i flashed the codes off the ecu and i got:
1. knock sensor 1: no change in voltage.
2. AFM: Low voltage.
3. Oxygen sensor : no change in voltage.
But ive fitted new AFM an oxygen sensors but the codes may still be on the ecu even though ive unplugged it lol.
One idea is once you got the problem sorted take the feed to the battery off and leave it overnight to clear the codes. helped with me!
If the knock sensor & ICV plugs are incorrectly wired (common) you get those faults. + a bad idle as the signal for the ICV will be going to the knock sensor.
The knock sensor detects the detonation & the ECU uses this to retard the timing until det stops.
What colour plugs go to the them then craig think ive got red to knock and black to icv?
Just to make sure thsat the connectors are the right way round on the ICV an knock sensor if i squeeze the ICV pipe tight that goes to the SFI box should i notice a change in tickover speed as when i squeeze mine nothing happens at all so im wondering if thats my problem.
Just to make sure thsat the connectors are the right way round on the ICV an knock sensor if i squeeze the ICV pipe tight that goes to the SFI box should i notice a change in tickover speed as when i squeeze mine nothing happens at all so im wondering if thats my problem.
Anyone any ideas on this one ^^^^.
Red goes to knock yes iirc.
Yes if you squeeze the icv pipe the engine should start dying as theres no where else it can get air from, unless its got an air leak.
let_nova
07-03-10, 10:27 AM
very true adam, if you squeeze it tight you will hear it dying and trying to suck air. if its not doing this i say you have a massive air leak.
djbrowney
07-03-10, 10:37 AM
If the knock sensor & ICV plugs are incorrectly wired (common) you get those faults. + a bad idle as the signal for the ICV will be going to the knock sensor.
The knock sensor detects the detonation & the ECU uses this to retard the timing until det stops.
if they are round the wrong way the engine will run for a few seconds and the cut out, as said in you want to change the fuel you use. i had this problems with tesco petrol. used to bring the knock sensor up as a fault. changed the fuel i was using and never had a problem again !
if the fuel has been sitting about it can loose it octane value and will cause problems !
Red goes to knock yes iirc.
Yes if you squeeze the icv pipe the engine should start dying as theres no where else it can get air from, unless its got an air leak.
Right i need to try this again tomorrow as the last time i did this nothing happened :tard: .
if they are round the wrong way the engine will run for a few seconds and the cut out, as said in you want to change the fuel you use. i had this problems with tesco petrol. used to bring the knock sensor up as a fault. changed the fuel i was using and never had a problem again !
if the fuel has been sitting about it can loose it octane value and will cause problems !
Right well the engine runs properly so i think these are the right way round then and as for the fuel i always use jet or shell something like that so no idea on that one.
djbrowney
07-03-10, 07:34 PM
well if you have shell v power it could have been sat in the tank six month because it to bloody expensive, just try driving it on another tank of something else mate !
well if you have shell v power it could have been sat in the tank six month because it to bloody expensive, just try driving it on another tank of something else mate !
Its just the normal stuff mate lol tryed unplugging the knock sensor and it does nothing dosent even send the managment light on but it will still come on at 3000rpm lol.
djbrowney
07-03-10, 07:45 PM
unplugging it wont do anything but only bring on the eml
unplugging it wont do anything but only bring on the eml
It doesnt bring it on though untill 3000rpm which it find strange even with it unplugged?
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