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https://yabb.autonerdz.com/cgi/yabb2//YaBB.pl >> >> Cop Coil Primary waveform https://yabb.autonerdz.com/cgi/yabb2//YaBB.pl?num=1487370109 Message started by James H on Feb 17^th, 2017 at 2:21pm

Title: Cop Coil Primary waveform
Post by James H on Feb 17^th, 2017 at 2:21pm

Thought I would post this for those of us less knowledgeable an example of a Cop Coil Primary waveform from a Suzuki GSXR750 Fuel Injected bike with a fouled spark plug.

https://yabb.autonerdz.com/cgi/yabb2//YaBB.pl?action=downloadfile;file=gsxr.pdf (478 KB | )

Title: Re: Cop Coil Primary waveform
Post by rayray on Feb 18^th, 2017 at 1:54pm

The fouled plug is the pink or purple trace?

The blue trace looks like it has no spark time?

I guess the red trace is the injector amps?

The COP coil with the fouled spark plug, can it fire a spark tester set at 30kv?

Ray

Title: Re: Cop Coil Primary waveform
Post by James H on Feb 19^th, 2017 at 10:34am

Ray, the blue trace is the fouled plug. I'm not sure about peak coil output but it easily jumped a spark tester gap of a 10mm or so. Red was the current. The pink is a good cyl for reference.

James

Title: Re: Cop Coil Primary waveform
Post by rayray on Feb 19^th, 2017 at 4:47pm

The spark tester gap of 10 mm is .394 inches, which is less than half an inch. The recommended Ford COP spark test is three quarters of an inch or 19 mm.

The blue trace is the fouled plug. Is it oil fouled or is it wet, fuel fouled? Is there a carbon track on the spark plug insulator or in the COP boot?

The red 1 amp trace would show an injector resistance of about 14 ohms and I think I can see the injector opening humps.

Ray

Title: Re: Cop Coil Primary waveform
Post by James H on Feb 20^th, 2017 at 5:25am

It was fuel fouled. The spec for injector resistance is 11-13 ohms. Thanks for the tip on the spark gap.