The Autonerdz Community Forums
https://www.autonerdz.com/cgi/yabb2/YaBB.pl
General Public Area >> PicoScope >> Any thoughts ??
https://www.autonerdz.com/cgi/yabb2/YaBB.pl?num=1584809206

Message started by Manic Mechanic on Mar 21st, 2020 at 9:46am

Title: Any thoughts ??
Post by Manic Mechanic on Mar 21st, 2020 at 9:46am
1995 4.0 Jeep Cherokee , Someone has thrown many new parts at it , Won't pass smog at 15mph Nox too high , 25mph too , Ran this quick scope pattern and the spark line looks bad , Any thoughts why ??

https://www.autonerdz.com/cgi/yabb2/YaBB.pl?action=downloadfile;file=95_4_0_Quick_snap_coil_polarity_correct.psdata (4624 KB | 221 )
Sprkln_sml.jpg (37 KB | 136 )

Title: Re: Any thoughts ??
Post by Logic on Mar 21st, 2020 at 3:33pm
Further reading

https://www.searchautoparts.com/motorage/training/scoping-secondary-ignition-systems

Title: Re: Any thoughts ??
Post by Manic Mechanic on Mar 22nd, 2020 at 10:39am
Thanks for the link , A lot of great information

Title: Re: Any thoughts ??
Post by fisher on May 13th, 2020 at 10:18am
I dont know if you solved this. NoX is a gas formed when nitrogen in the air burns ( oxides of nitrogen). In a laboratory burn, gasoline wont burn the nitrogen in the air you breathe, it produces carbon dioxide and water. Nitrogen is 78 % or so of the air you breathe. If the combustion temperature gets hot enough the high 20 something thousand degrees fahrenheit, the nitrogen burns. Our bodies evolved inhaling and exhaling the nitrogen as an inert gas that it did not use; we need the oxygen. If you burn the nitrogen you now will be breathing the charred stuff. Nitrogen burned or NoX produces the brown smog California was infamous for.
   You can run  a car well without egr valve and hot temperatures and high pressure equal high power but also, burned nitrogen. Hence the egr system; the recycled exhaust is an inert (cant reburn) and reintroduced into the mix at calibrated amounts serves to lower combustion temps as they displace burnable fuel.
As said, high temps and high pressure equal high performance and if your egr wasn't working I suppose your secondary sparkline would reflect a normal burn. Your sixties vintage high performance rig would show a normal sparkline, burned nitrogen or not.
I am thinking this can have been caused by carbon piling up on top of the piston, causing pressures to in crease in the combustion chamber as they displace space.
  So did you figure this one out?

Title: Re: Any thoughts ??
Post by fisher on Aug 1st, 2021 at 9:23pm
Nobody replied. I never saw my mistake. I meant the high 2000 something degrees fahrenheit, not 20,000.

Title: Re: Any thoughts ??
Post by Logic on Aug 1st, 2021 at 10:29pm

fisher wrote on Aug 1st, 2021 at 9:23pm:
Nobody replied. I never saw my mistake. I meant the high 2000 something degrees fahrenheit, not 20,000.


Temperature of the sun  9,941°F  ;)

The Autonerdz Community Forums » Powered by YaBB 2.5 AE!
YaBB Forum Software © 2000-2010. All Rights Reserved.