An ignition question

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An ignition question

Postby Chris_W » Tue Feb 19, 2013 2:55 pm

Corsa 1.0 X10XEP with no start and no codes set, according to the customer it was driven approximately 2 miles and then parked up. They have had a good go at this one themselves so it's got a second hand fuel pump, coil pack and air flow meter.

Plenty of fuel, I appear to have injector drivers and wet plugs but will not fire up on anything (even a sniff) so I thought I would start with the spark so got the scope out. I am not 100% sure yet what I am looking at but I am not sure that it should look like the attached file?

If it should then please feel free to ignore me... But if not then what could cause it to look this way? I've not really had much to do with these yet so I am just learning... :oops:
Attachments
corsa coil.psdata
(391.6 KiB) Downloaded 358 times
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Re: An ignition question

Postby Robski » Tue Feb 19, 2013 4:25 pm

Chris,

For starters your sample rate is insufficient for such a capture, 51 times slower than it should be !!

Secondly i don't recall these being a multi-strike system ??

Grab a CMP/CKP capture & let's see what's occurring ??

PS email me if you desire ?
I can create you a settings file if you want ??
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Re: An ignition question

Postby Chris_W » Mon Feb 25, 2013 8:05 pm

So after a bit of advice, and some training I have looked at this one again.

Question, is the amplitude of the crank sensor enough?

Anyone got a reference to compare for Cam/Crank sync?

Image

I don't seem to be able to resize the image right now (I think that is me though)?

ChA Ign primary Cyl1
ChB Ign Amps
ChC CKP Signal
ChD CMP Signal
Attachments
Corsa no start CKP CMP Pri#1 Coil amps.psdata
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Re: An ignition question

Postby Fat Freddy » Tue Feb 26, 2013 3:34 am

AC coupled on channel C?


HTH
FF
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Re: An ignition question

Postby Robski » Tue Feb 26, 2013 4:12 am

VR CKP sensor ;)
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Re: An ignition question

Postby Fat Freddy » Tue Feb 26, 2013 4:35 am

VR CKP sensor


Yer. I had thought about that before posting. I don't use AC coupling myself as I want to know exactly whats happening. The rejection of low sigal frequecies is probably what bothers me.

AC coupling. In this mode, the scope device rejects very low signal frequencies below about 1 hertz. This allows you to use the full resolution of the scope to measure a.c. signals accurately, ignoring any d.c. offset. You cannot measure the signal level with respect to ground in this mode.



Perhaps a refreasher is required for me.

FF
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Re: An ignition question

Postby Robski » Tue Feb 26, 2013 5:27 am

hello FF

it's each to there own mate on the AC/DC coupling on VR CKP sensors,he will be taking another DC coupled along with other captures.

I personally DC couple but created that settings file for Chris & gave him the option to change the coupling to DC,I was going to do that but I'm sure someone would have come on saying it should be AC coupled......each to there own.
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Re: An ignition question

Postby Robski » Tue Feb 26, 2013 7:17 am

just to clear any confusion one of the main reasons for me AC coupling the CKP was to clean the signal to show if there was any teeth damage as the ign multi striking seems odd. I personally DC couple as stated.
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Re: An ignition question

Postby KimAndersen » Wed Feb 27, 2013 10:06 am

Hi

The amplitude looks very small - only at 690 millivolt peak to peak and when I have seen some ECU specification´s claiming at least 700 mV for the ECU to recognize the signal - so I would say it looks a little bit suspect.

One thing to remember when we are dealing inductive sensor´s is the engine RPM - so low RPM is equal a small amplitude and high RPM is equal bigger amplitude.

I´m well aware - that it does not explain why the engine suddenly stops - when it is running.

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Re: An ignition question

Postby hijakd » Thu Jul 17, 2014 12:08 pm

Hi I could be mistaken but from most of the cam/crank captures iv seen/taken urs looks out here's a cam/crank I took after a repair
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image.jpg
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