have a look at the 2 screen captures ive added

this is on a 4ch automotive kit

one is with HT lead on number 2 and the other on number 3

the other pic is CHA on coil lead and CHB on lead 1

http://members.optusnet.com.au/~t.marriott/mypic1.JPG

why doesnt CHB have 6 times more events (for want of a better word) than CHA...CHB is the coil and for each spark on CHA the coil should be firing the other cyls

http://members.optusnet.com.au/~t.marriott/mypic4.JPG

now on this one why does CHA and CHB fire at the same time? shouldnt CHA fire then latter CHB fire. why is the scope showing them firing at the same time

the car is a 1987 bmw 325i

The images were captured at idle (1000 rpm). I calculate that each cylinder should fire every 120ms and the coil should fire every 20ms...

there should also be somekind of delay between cha and chb if they are set up on different cyls

what am i not getting here??

did some detective work tonight...

it seems that the pickups are picking up signals from other spark leads or the coil

if anyone is familiar with the layout of the E30 6cyl engine bay then ull know that the coil lead runs very close to spark leads. I found that if i put the inductive clamps on cyls 5 and 6 then i got a much better result. each lead was still picking up signals from other leads or the coil but not as badly.

The pico inductive clamps dont appear to work that well, or maybe too well. I found that i dont even need to put the clamp over the lead, instead i can just put it near the lead and i get a strong signal...

to me this is not very good, gunna have to find a way around this

Hi Gogeta

Try just using one inductive lead connected to the coil wire as close to the coil as possible and don’t use the trigger function and show results.
Then use an injector on the other channel to trigger off and post the results

Where did you purchase your Pico?
Where are you posting from?

Mick

hi there....

whats the theory behind using an injector signal as a trigger? would it matter if the system was sequential or batch injection??

im posting from melbourne australia
i bought the kit from emona instruments in melboourne...didnt know about autonerdz at the time and also was looking for local backup if something turned out to be a dud

Gogetta,

We handle the specific PicoScope help questions in our Picogroup areas.  You are welcome to subscribe.  We have quite a few Aussie members.  

I think you have already answered your own question.  You can clearly see from your second image above that the first event on A is the #2 firing.   The #3 firing on B occurs just before 67ms on the time scale.  The rest are ghost firings from adjacent wires.

The wire type can influence this ghosting effect.  Suppression wires reduce it solid core wires increase it.  Also close the proximity of the wires to the capacitive pickup show this more.


Quote:

whats the theory behind using an injector signal as a trigger?

I would not use injection to trigger ignition captures.  The injection timing can vary based on RPM and load and doesn't always fire where you think it does.  I would use the capacitive probe or an inductive probe on a plug wire.


Quote:

i bought the kit from emona instruments in melboourne...didnt know about autonerdz at the time and also was looking for local backup if something turned out to be a dud

That's good.  We encourage overseas customers to buy locally.  In spite of this, we still have customers on six continents.  :o
Some insisted on purchasing through us and some subscribe to our support and training package.

Gogetta wrote on Mar 21^st, 2008 at 8:02am:

hi there.... whats the theory behind using an injector signal as a trigger? would it matter if the system was sequential or batch injection??

Using just the coil wire at the coil will give you endless plug firings. So adding an injector as a trigger will help you figure out the firing order in sequential fired injectors. I wouldn’t believe this vehicle would be batched fired.
Of course this would solve your RFI problem in the plug wires you seem to be having.

Sign up with Tom and get a better understanding of the sample rate your scope is capable of.
The support  he will give is excellent.



Quote:

im posting from melbourne Australia

I would have loved to hook up my Pico to those F1 cars there last week.


Quote:

i bought the kit from emona instruments in melboourne...didnt know about autonerdz at the time and also was looking for local backup if something turned out to be a dud

I hate it when people sell things without the support.

Dont give up hope, read as much as you can and experiment on known good vehicles.

Mick

Tom Roberts wrote on Mar 21^st, 2008 at 8:28am:

Gogetta, We handle the specific PicoScope help questions in our Picogroup areas.  You are welcome to subscribe.  We have quite a few Aussie members.   The wire type can influence this ghosting effect.  Suppression wires reduce it solid core wires increase it.  Also close the proximity of the wires to the capacitive pickup show this more.  I would use the capacitive probe or an inductive probe on a plug wire.

what type of probes are the ones that come in the pico kit?? capacitive or inductive?

how would i go about subscribing???

thanks for the help so far, its a good thing i dont mind a challenge.

The Secondary probes that come in the Pico kits are capacitive.  An inductive probe just outputs a spike when the plug fires.  

The web site does not take orders from outside the USA but you can still order.   We just have to take your order manually.  We take Pay Pal, which works really well for international.  And there are other options.  The full Autonerdz PicoScope support and training package subscription is $650 USD annually.

Email or PM me for more details and to arrange your order.