Knock sensor control

[Peter Wales]

I remember reading something about this new system some time ago. As I
remember, immediately after the ignition pulse, the ignition system puts a
voltage (I think about 100v) across the plug. The gas inside the combustiuon
chamber is ionised and so a current will flow. The current indicates the
status of the combustion.

I assume if it pinged, the combustion ionisation will be different than if
it fired normally. Exactly how, I don't know. Interesting subject though.


Peter Wales

At 08:01 AM 3/7/95 -0500, DIY_EFI at coulomb.eng.ohio-state.edu wrote:
>
>>> The signal contains a lot of info, but it isn't easy to
>>> extract it from each firing at 5000 rpm.
>>
>>	Just what is the information and how do you get it.  The little
>>I've heard about the Sabb system is that they use it for a knock sensor. 
>>It sounds like it would take alot of testing to know what the output means.
>>
>>
>>Henry Sommer | gt0035b at prism.gatech.edu | Georgia Institute of Technology
>
>You're right.  it does take a lot of testing to get the info out of the
>signal.  Mecel is currently working on knock detection, cam position
>detection, misfire, preignition, and air/fuel ratio detection.  Huge efforts
>have been undertaken by people in universities, Mecel, and Delco to try to
>realize these functions and good results have been achieved.  I can't
>provide any details, unfortunately, but I also don't think a person with a
>soldering iron can get any useful signal out of a spark plug.  The benefits
>to a car company are evident, especially if the individual sensors mentioned
>above can be deleted from the system.  That's why we are working so hard on
>this.
>
>Andy Voss                 
>Advanced Powertrain Systems     c23ahv at kocrsv01.delcoelect.com 
>Delco Electronics Corp.         (317)451-0415    GM:8-322-0415
>
>"If you always do what you always did, you will always get what you always
>got." - Unknown
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