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https://yabb.autonerdz.com/cgi/yabb2//YaBB.pl General Public Area >> Test Board >> Secondary waveform test #2 https://yabb.autonerdz.com/cgi/yabb2//YaBB.pl?num=1349230882 Message started by BowtieBob on Oct 2^nd, 2012 at 6:21pm

Title: Secondary waveform test #2
Post by BowtieBob on Oct 2^nd, 2012 at 6:21pm

This is a secondary waveform with the correct polarity. Car is a 1999 Chevy Cavalier 2.2 engine with 212,000 miles. (just posting to get familiar with correct way to post)

https://yabb.autonerdz.com/cgi/yabb2//YaBB.pl?action=downloadfile;file=Cavalier_cylinder__2_secondary_waveform.psdata (175 KB | )

Title: Re: Secondary waveform test #2
Post by PRESTON on Oct 2^nd, 2012 at 6:54pm

Looking good...

CAVALIER_SECONDARY_2.jpg (146 KB | )

Title: Re: Secondary waveform test #2
Post by BowtieBob on Oct 2^nd, 2012 at 7:03pm

Thanks Preston, do you notice anything unusual in the waveform?

Title: Re: Secondary waveform test #2
Post by PRESTON on Oct 2^nd, 2012 at 7:32pm

Not really, should I?

Title: Re: Secondary waveform test #2
Post by Tom Roberts on Oct 2^nd, 2012 at 7:58pm

Is it realy firing at just over 3 KV?

That's a LOT of sample rate so there is a bit of noise that makes it look higher but a zoom zoom shows about 3.4 KV....

Title: Re: Secondary waveform test #2
Post by PRESTON on Oct 2^nd, 2012 at 8:02pm

I never thought to zoom in on it Tom, from out here it looked like 9kv and I didn't think much about it, plus the burn looked pretty good, just over 1ms.

Title: Re: Secondary waveform test #2
Post by Erik_1940 on Oct 2^nd, 2012 at 8:11pm

:question

cavalier_2_secondary.gif (11 KB | )

Title: Re: Secondary waveform test #2
Post by RtOne on Oct 3^rd, 2012 at 10:09am

Tom and Preston, What you guys are referring to is the point where the mixture ionizes and the fire lights, (Spark Jumps the Gap) ? Then the voltage will drop to a level where the fire stays lit ?

Cav_Secondary.gif (61 KB | )

Title: Re: Secondary waveform test #2
Post by PRESTON on Oct 3^rd, 2012 at 10:51am

RtOne wrote on Oct 3^rd, 2012 at 10:09am:

What you guys are referring to is the point where the mixture ionizes and the fire lights, (Spark Jumps the Gap) ?

Yes, I call that the firing KV also known as the spark KV ( at least in my head ).

RtOne wrote on Oct 3^rd, 2012 at 10:09am:

Then the voltage will drop to a level where the fire stays lit ?

I call this section the burn KV

Title: Re: Secondary waveform test #2
Post by RtOne on Oct 3^rd, 2012 at 1:49pm

Thank you Preston, I've never had occasion to zoom in that close, (the Sun I Trained on 30+ years ago couldn't) so I never knew the value. Nomenclature being of the essence, I thought I'd better get on your page. I'll watch a few more to see if that second dip is a common on the Burn KV Line, while zoomed in that far.

Title: Re: Secondary waveform test #2
Post by BowtieBob on Oct 3^rd, 2012 at 5:37pm

Thanks for all the input, this helps me in understanding more about diagnosing the waveform. One question that I have is what would be a good sample rate to use to capture the best picture? A little bit of info on the car.... it has no codes, no drive-ability problems, other than the customer complained of slightly lower fuel mileage, and slight loss of power, but says the car runs smooth with no misfires. Thanks again for your input

Title: Re: Secondary waveform test #2
Post by Mick on Oct 3^rd, 2012 at 6:11pm

BowtieBob wrote on Oct 3^rd, 2012 at 5:37pm:

One question that I have is what would be a good sample rate to use to capture the best picture?

1MS/s
You will find the answer to your question in the Picogroup area.

Title: Re: Secondary waveform test #2
Post by BowtieBob on Oct 4^th, 2012 at 5:25pm

Thanks Mick for your response