to test KS while motor operation....
04-10-2005, 02:15 PM
#1
Guest
Posts: n/a
to test KS while motor operation....
I was wondering....If you put in a resistor on the ECU side of the KS harness.....wouldn't you be able to run the car...and have your multi meter on the harness going to the KS, to see the ohm's while its in operation, and see if they go up and down, indicating either engine knocking or a bad KS....Just a thought that occured in my head, has anyone tried this before? or would it not work, or even cause damage???
04-10-2005, 02:19 PM
#2
Originally Posted by blacks92seAuto
I was wondering....If you put in a resistor on the ECU side of the KS harness.....wouldn't you be able to run the car...and have your multi meter on the harness going to the KS, to see the ohm's while its in operation, and see if they go up and down, indicating either engine knocking or a bad KS....Just a thought that occured in my head, has anyone tried this before? or would it not work, or even cause damage???
You could do that, but what would you really be able to gain from it? How would you be able to distinguish between a "normal" KS signal and a bad one if you don't have a "good" signal pattern to compare it to? And, yes, you will be exposing your car to risk, because the ECU won't be compensating for anything the KS is seeing.
04-10-2005, 07:56 PM
#6
Guest
Posts: n/a
well, the ecu doesn't tell you everything, even when stuff is going bad, especially if its an intermitent problem.
I thought the knock sensor would stay at 560k ohm or whatever when it was running normal, and if it picks up knock it either sends more or less to the ecu to tell it to retard the timing....but I don't know much, it was just a thought...my dad has an oscilliscope in the shed...hasn't used it in over 10 years lol
I thought the knock sensor would stay at 560k ohm or whatever when it was running normal, and if it picks up knock it either sends more or less to the ecu to tell it to retard the timing....but I don't know much, it was just a thought...my dad has an oscilliscope in the shed...hasn't used it in over 10 years lol
04-10-2005, 08:53 PM
#7
If you wanted to test the ks, then the 'consult diagnostic tool' from nissan is the way to go. It'll give a real time engine timming readout. And thats apart of testing if the sensor is bad, by doing a WOT from a stop and see how much the timming is retarding.
04-11-2005, 08:03 AM
#8
Senior Member
Join Date: Mar 2002
Location: Ontario, Canada
Posts: 1,114
A bit of theory: the ECU can sense if resistance of the KS is not 500 KOhm. That is quite easy to test. When the KS is an open circuit or short, the ECU will raise the codes.
But the KS, which has nominal conductivity, but does not report any knocking, is not something that ECU can figure out, because absense of knocking is normal operation. The ECU does not receive any signal and thinks it is normal and continues to set timing to whatever it is set to, helping to destroy the heads, plugs and pistons while knocking continues.
This is the case when external diagnostic tool is required, like Eric pointed out. It can be CONSULT (or oscilloscope, if you manage to cause knocking by advancing the timing and clearly see the spikes). I could not manage to cause knocking last time I tried. I advanced as much as I could with disconnected KS (to like 35°) and still never had any pinging. Still puzzled if the KS is good or bad.
But the KS, which has nominal conductivity, but does not report any knocking, is not something that ECU can figure out, because absense of knocking is normal operation. The ECU does not receive any signal and thinks it is normal and continues to set timing to whatever it is set to, helping to destroy the heads, plugs and pistons while knocking continues.
This is the case when external diagnostic tool is required, like Eric pointed out. It can be CONSULT (or oscilloscope, if you manage to cause knocking by advancing the timing and clearly see the spikes). I could not manage to cause knocking last time I tried. I advanced as much as I could with disconnected KS (to like 35°) and still never had any pinging. Still puzzled if the KS is good or bad.
04-11-2005, 08:20 AM
#10
Senior Member
Join Date: Mar 2002
Location: Ontario, Canada
Posts: 1,114
Guess, Wiking will eventually see this thread and pitch in. I saw an oscillogram of KS while in pinging on his cardomain page, but I could never reproduce that.
Wiking: how are we supposed to correctly use oscilloscope for KS testing? What frequency is yours? I am using a 50 MHz Hitachi - is that enough? What is the length and voltage of a ping spike? I am seeing some low voltage alternating noise and very short spikes about 5 times the noise voltage in + and -. Should have put down the settings I used, but have forgotten. I will redo and repost anyway soon.
Wiking: how are we supposed to correctly use oscilloscope for KS testing? What frequency is yours? I am using a 50 MHz Hitachi - is that enough? What is the length and voltage of a ping spike? I am seeing some low voltage alternating noise and very short spikes about 5 times the noise voltage in + and -. Should have put down the settings I used, but have forgotten. I will redo and repost anyway soon.
04-11-2005, 02:00 PM
#11
Originally Posted by Tarzan
A bit of theory: the ECU can sense if resistance of the KS is not 500 KOhm. That is quite easy to test. When the KS is an open circuit or short, the ECU will raise the codes.
But the KS, which has nominal conductivity, but does not report any knocking, is not something that ECU can figure out, because absense of knocking is normal operation. The ECU does not receive any signal and thinks it is normal and continues to set timing to whatever it is set to, helping to destroy the heads, plugs and pistons while knocking continues.
This is the case when external diagnostic tool is required, like Eric pointed out. It can be CONSULT (or oscilloscope, if you manage to cause knocking by advancing the timing and clearly see the spikes). I could not manage to cause knocking last time I tried. I advanced as much as I could with disconnected KS (to like 35°) and still never had any pinging. Still puzzled if the KS is good or bad.
But the KS, which has nominal conductivity, but does not report any knocking, is not something that ECU can figure out, because absense of knocking is normal operation. The ECU does not receive any signal and thinks it is normal and continues to set timing to whatever it is set to, helping to destroy the heads, plugs and pistons while knocking continues.
This is the case when external diagnostic tool is required, like Eric pointed out. It can be CONSULT (or oscilloscope, if you manage to cause knocking by advancing the timing and clearly see the spikes). I could not manage to cause knocking last time I tried. I advanced as much as I could with disconnected KS (to like 35°) and still never had any pinging. Still puzzled if the KS is good or bad.
Advancing the timming gives lower timming not higher numbers. Advancing means the mixture is lite sooner, not later.
04-11-2005, 06:25 PM
#12
Senior Member
Join Date: Dec 2004
Location: EU Scandinavia
Posts: 4,323
Originally Posted by Tarzan
Guess, Wiking will eventually see this thread and pitch in. I saw an oscillogram of KS while in pinging on his cardomain page, but I could never reproduce that.
Wiking: how are we supposed to correctly use oscilloscope for KS testing? What frequency is yours? I am using a 50 MHz Hitachi - is that enough? What is the length and voltage of a ping spike? I am seeing some low voltage alternating noise and very short spikes about 5 times the noise voltage in + and -. Should have put down the settings I used, but have forgotten. I will redo and repost anyway soon.
Wiking: how are we supposed to correctly use oscilloscope for KS testing? What frequency is yours? I am using a 50 MHz Hitachi - is that enough? What is the length and voltage of a ping spike? I am seeing some low voltage alternating noise and very short spikes about 5 times the noise voltage in + and -. Should have put down the settings I used, but have forgotten. I will redo and repost anyway soon.
The problem is me stupido got no sense on the oscilloscope. What u see on my website, is a signal produced by a definitely dead KS. Could not really figure out wassup. Its was an digital HP with auto trig: all settings viewavble (no real hlp).
My poor opinion is, that the only way to 'diagnose' KS is on the run as idling will not ever cause ping... Nissan has their onboard diag tool and may be possible to diag that. For mee, the 'diag' is the bypass resistor and ah the feeling of pwr...
--->mind u, using 95 octane bck home, cause cannot get anything else
(Btw. This non scandic keyboard sucks. Errors x100... and dont anyone say I am on the drugs. Anybody saying that, does not know cow pee worth of intl traveling.....)
04-11-2005, 10:16 PM
#13
holly crap you got
Originally Posted by Wiking
By chance saw this, currently on trip in colorado. (Missing our six feet moss quitoes over blizzard 2005..)
The problem is me stupido got no sense on the oscilloscope. What u see on my website, is a signal produced by a definitely dead KS. Could not really figure out wassup. Its was an digital HP with auto trig: all settings viewavble (no real hlp).
My poor opinion is, that the only way to 'diagnose' KS is on the run as idling will not ever cause ping... Nissan has their onboard diag tool and may be possible to diag that. For mee, the 'diag' is the bypass resistor and ah the feeling of pwr...
--->mind u, using 95 octane bck home, cause cannot get anything else
(Btw. This non scandic keyboard sucks. Errors x100... and dont anyone say I am on the drugs. Anybody saying that, does not know cow pee worth of intl traveling.....)
The problem is me stupido got no sense on the oscilloscope. What u see on my website, is a signal produced by a definitely dead KS. Could not really figure out wassup. Its was an digital HP with auto trig: all settings viewavble (no real hlp).
My poor opinion is, that the only way to 'diagnose' KS is on the run as idling will not ever cause ping... Nissan has their onboard diag tool and may be possible to diag that. For mee, the 'diag' is the bypass resistor and ah the feeling of pwr...
--->mind u, using 95 octane bck home, cause cannot get anything else
(Btw. This non scandic keyboard sucks. Errors x100... and dont anyone say I am on the drugs. Anybody saying that, does not know cow pee worth of intl traveling.....)
04-12-2005, 06:04 AM
#14
Senior Member
Join Date: Mar 2002
Location: Ontario, Canada
Posts: 1,114
Hey kc10fish: your 91 equals his 95. RON versa ROZ, ya know...
Wiking:
I pour in platinum, that's probably why I could not get any ping in idle. When I had VW Passat '81, whos distributor was not restricted within a small range of angles, I could easily force knocking in idle with whatever gas in the tank. The next thing I am going to try will be filling 5 liter of 89 into an empty tank, driving, re-filling with another 5 liter of 89 and testing again. Too bad my digital camera sucks, I wanna post a screen for a discussion.
Wiking:
I pour in platinum, that's probably why I could not get any ping in idle. When I had VW Passat '81, whos distributor was not restricted within a small range of angles, I could easily force knocking in idle with whatever gas in the tank. The next thing I am going to try will be filling 5 liter of 89 into an empty tank, driving, re-filling with another 5 liter of 89 and testing again. Too bad my digital camera sucks, I wanna post a screen for a discussion.
04-12-2005, 08:00 AM
#15
Senior Member
Join Date: Dec 2004
Location: EU Scandinavia
Posts: 4,323
Originally Posted by Tarzan
Hey kc10fish: your 91 equals his 95. RON versa ROZ, ya know...
Wiking:
I pour in platinum, that's probably why I could not get any ping in idle. When I had VW Passat '81, whos distributor was not restricted within a small range of angles, I could easily force knocking in idle with whatever gas in the tank. The next thing I am going to try will be filling 5 liter of 89 into an empty tank, driving, re-filling with another 5 liter of 89 and testing again. Too bad my digital camera sucks, I wanna post a screen for a discussion.
Wiking:
I pour in platinum, that's probably why I could not get any ping in idle. When I had VW Passat '81, whos distributor was not restricted within a small range of angles, I could easily force knocking in idle with whatever gas in the tank. The next thing I am going to try will be filling 5 liter of 89 into an empty tank, driving, re-filling with another 5 liter of 89 and testing again. Too bad my digital camera sucks, I wanna post a screen for a discussion.
Yess, that would be a valid tst. But still there should be a display (for me to be satisfied) to always tell your firing angle while driving, especially when loading the engine... otherwise dont wanna have KS toy. Even if its safety poofed.
"95 oct. we slum down here only have 91 oct. in california.....you lucky person you ! how ya been?"
- jetlag just loosenin its grip along with blizzard 2005, got even my luggage yesterday (yes lucky me, last time did not)...
Thread
Thread Starter
Forum
Replies
Last Post
tarun900
4th Generation Maxima (1995-1999)
19
12-20-2021 06:57 PM
AaronL
5th Generation Maxima (2000-2003)
15
08-08-2020 10:31 AM
CAN-Toronto FS: Basement cleaning
knight_yyz
5th Generation Classifieds (2000-2003)
12
11-01-2015 01:34 PM