Strange pattern

Ask for and share advice on using the PicoScope kit to fix vehicles here.

Strange pattern

Postby terbo » Sat Jul 19, 2014 8:43 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
Holding at 3000
(3.53 MiB) Downloaded 147 times
Strange Pattern 2x
(784.04 KiB) Downloaded 137 times
strange pattern 1
(3.71 MiB) Downloaded 121 times
Posts: 46
Joined: Sun Jul 06, 2014 2:40 pm

Re: Strange pattern

Postby rkelsey » Sat Jul 19, 2014 9:19 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?

User avatar
Posts: 3
Joined: Sat Jul 19, 2014 7:03 pm
Location: London, UK

Return to Diagnostic discussion

Who is online

Users browsing this forum: No registered users and 0 guests