- Sun Dec 03, 2023 8:42 am
#66109
Ok guys I'm not afraid to be proven wrong, I'm no expert and I'm always willing to learn from mistakes. I begged, borrowed a scope from work and had a closer look at the VR and spark signals. First off, working off information from this forum and elsewhere this is my VR signal pre n post conditioner. Looks about right, hahah hope it's right.
I'm using a MAX9924 based conditioner on 202207.1 code and all test was done on bench.
Spent few days on this, initially comparing the spark signal output from the board vs the spark event at the spark plug but found almost no delay there and was convinced that all the delay I'm seeing is caused by the timing light. Packed up all the bench test stuff and was done. But somehow sleep on it and just thought why not test spark event vs ignition timing signal. This is when I found something interesting, tests here done with these settings trigger angle at 180deg, fixed timing at 0 deg and fixed dwell at 3ms.

First n second image shows test done at 1k rpm. Not sure why but I'm seeing 280uSec (sometimes up to320uSec) error between vr output signal into ecu vs spark event.


These next image is test done at 5k rpm and now the error comes down to 60uSec.


When I tried trigger angle at 0 deg I'm seeing almost no error at 1k rpm right up to 5k rpm and the trend is increase in error as I go higher trigger angle right up to 180 deg. The puzzling thing to me is if there's wrong setup in vr setting or setup, why does the error only increases off 0 deg?
This dun seem normal but I'm just unsure what to make of it, I've checked vr polarity seems correct. So in my case I've trigger angle at 161deg and I'm guessing I'm starting out at an advanced timing and I'm seeing it retard as I go up in speed?

I'm using a MAX9924 based conditioner on 202207.1 code and all test was done on bench.
Spent few days on this, initially comparing the spark signal output from the board vs the spark event at the spark plug but found almost no delay there and was convinced that all the delay I'm seeing is caused by the timing light. Packed up all the bench test stuff and was done. But somehow sleep on it and just thought why not test spark event vs ignition timing signal. This is when I found something interesting, tests here done with these settings trigger angle at 180deg, fixed timing at 0 deg and fixed dwell at 3ms.

First n second image shows test done at 1k rpm. Not sure why but I'm seeing 280uSec (sometimes up to320uSec) error between vr output signal into ecu vs spark event.


These next image is test done at 5k rpm and now the error comes down to 60uSec.


When I tried trigger angle at 0 deg I'm seeing almost no error at 1k rpm right up to 5k rpm and the trend is increase in error as I go higher trigger angle right up to 180 deg. The puzzling thing to me is if there's wrong setup in vr setting or setup, why does the error only increases off 0 deg?
This dun seem normal but I'm just unsure what to make of it, I've checked vr polarity seems correct. So in my case I've trigger angle at 161deg and I'm guessing I'm starting out at an advanced timing and I'm seeing it retard as I go up in speed?