Strange pattern

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Strange pattern

Postby terbo » Sat Jul 19, 2014 10:43 pm


Today i played around with a 2002 Fiat Stilo 1,6 16V.
And because of easy to get to, i tryed the current Loop on
the Fuse that controlls the Ignition Coils and the Injektors.

Looking at it at Idle or at 3000 rpm it looked not really bad.
But kicking the throttle produced some very strange Waveforms
i never got this normal ??

If i get a other car i will look and compare but just for intresst.

Greets Chris
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Re: Strange pattern

Postby rkelsey » Sat Jul 19, 2014 11:19 pm

I could be wrong, as I've only recently really got into scopes, but my opinion is that it looks ok to me.

It looks like your load is regular as you would hope for with injectors and coils, the load being whatever that fuse supplies.

The duration at 3000rpm on the larger peaks is much shorter [9.6ms] compared to idle [32ms] but the peaks are still at 7.25A. To me that looks like: INJECTION -- SPARK -- INJECTION -- SPARK (and so on.)

The duration of the smaller peaks at idle is 3.54ms and just shy of 780mA.

Compared to a 2.34ms duration at 3000 at about 800mA.

Any confirmation of my thoery?

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