measuring injector in closed loop

Ask any questions relating to the PicoScope hardware or kit contents here.
If you have any questions prior to purchasing the kit post them here.
Post Reply
Guest

measuring injector in closed loop

Post by Guest »

If a typical injector on time is about 4ms that is 4 thousandth of a second then how much does the ECU richen and lean the mixture in closed loop? If I can see an oxygen sensor cycling then how come a can’t see the injector pattern change?

User avatar
Autonerdz
TwoWaves
TwoWaves
Posts: 387
Joined: Wed Nov 20, 2002 4:19 pm
Location: Washington State USA

IPW

Post by Autonerdz »

You can see the injector pulse width change in closed loop but the changes are small. You will have to set the scope up with a lot of time on the screen, with maximum samples, so you can capture the injector and the O2 over enough time to see a couple of O2 cycles. You will also need to deploy some resolution enhance to the O2 signal to clean up some of the noise on that signal so you can see it clearly.

Then you can zoom in and use rulers to measure the IPW when the O2 is high and compare to when it is low. Then you will see the difference.

_________________
Tom Roberts
(The Picotologist)
http://www.autonerdz.com
skype: autonerdz
THE PicoScope Automotive Authority
In North America

Dave Hill
TwoWaves
TwoWaves
Posts: 63
Joined: Fri Jun 22, 2007 8:15 am

Post by Dave Hill »

On some cars the shift in injector pulse width in response to O2 sensor feedback is more pronounced than others. I took this capture way back & I still find it fascinating.

Image

Hope this helps

Dave

Post Reply