PicoScope 7 Automotive
Available for Windows, Mac, and Linux, the next evolution of our diagnostic scope software is now available.
Hello from a new chum
Hello from a new chum
Hello,
My name is Kim.
After 50 years engineering in the auto industry I still enjoy troubleshooting anything mechanical/electrical.
Stepping up from the trusty Fluke multimeter I recently bought my first scope, an affordable 2204a.
Of course that was only enough to whet my appetite so it was quickly pushed aside by a 4425 kit which is very satisfying to use.
I am in awe of the amazing insight it permits as one learns to interpret its signals.
Of great value is the wealth of training information available, both on Pico sites & youtube.
Currently I am attempting to discover the reason why my secondary ignition voltage trace fluctuates wildly, mainly on snap throttle (attached). Hours of searches, just not in the right place yet eh?
I would like to understand how it happens, even if it is an unavoidable scope artifact.
I am finding Pico's friendly Posters to be most informative & encouraging.
Keep up the good work everybody.
My name is Kim.
After 50 years engineering in the auto industry I still enjoy troubleshooting anything mechanical/electrical.
Stepping up from the trusty Fluke multimeter I recently bought my first scope, an affordable 2204a.
Of course that was only enough to whet my appetite so it was quickly pushed aside by a 4425 kit which is very satisfying to use.
I am in awe of the amazing insight it permits as one learns to interpret its signals.
Of great value is the wealth of training information available, both on Pico sites & youtube.
Currently I am attempting to discover the reason why my secondary ignition voltage trace fluctuates wildly, mainly on snap throttle (attached). Hours of searches, just not in the right place yet eh?
I would like to understand how it happens, even if it is an unavoidable scope artifact.
I am finding Pico's friendly Posters to be most informative & encouraging.
Keep up the good work everybody.
- Attachments
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- Secondary voltage waveform aberration.psdata
- (5.87 MiB) Downloaded 375 times
Re: Hello from a new chum
Hi Chum / Kim
Snap Throttle is the most Treacherous and Violent time in that combustion chamber.
For all we know you have posted a Known good waveform !!
Be good if we are on a level playing field.
Let us get the correct perspective on this. Is this waveform taken from a car that runs well or does it have negative symptoms, if so what are they?I would like to understand how it happens, even if it is an unavoidable scope artifact.
Snap Throttle is the most Treacherous and Violent time in that combustion chamber.
For all we know you have posted a Known good waveform !!
Be good if we are on a level playing field.
Re: Hello from a new chum
Thanks for your welcoming reply Iver.
During this learning period my aim is firstly to understand what I see happening on the screen.
Only then will I know if I can afford to ignore certain aberrations e.g. noise spikes, hash, shifting earth levels, etc.
Later my perspective will be (as yours) to fix the reported problem as quickly as possible by concentrating on symptoms.
By the way I have cleaned all engine bay earths & ensured good Autoprobe earthing.
I expect this "in your face" display has been technically explained somewhere so I will keep looking.
During this learning period my aim is firstly to understand what I see happening on the screen.
Only then will I know if I can afford to ignore certain aberrations e.g. noise spikes, hash, shifting earth levels, etc.
Later my perspective will be (as yours) to fix the reported problem as quickly as possible by concentrating on symptoms.
By the way I have cleaned all engine bay earths & ensured good Autoprobe earthing.
I expect this "in your face" display has been technically explained somewhere so I will keep looking.
Re: Hello from a new chum
Hi again !
On that vehicle there, you could introduce faults and look for the changes in the waveform. You can lower compression by leaving the hose loose and then manipulate ECT to make it run rich and lean.
However at snap throttle is always a difficult one as so much happens so quickly, not to say it cant be done.
What on that waveform concerns you, I see that you have 3 inductive Pick ups all on the same ht Lead, there will be minor differences ? You are not making a "Metal to Metal" Measurement more picking up a magnetic field after it has left the wire "so to speak" Even on a length of wire with a "Metal to Metal" you would see some Voltage drop (assuming current is flowing). More so with an accurate instrument such as Pico. We now digress into Voltage Drop, that is another story.
This is best achieved by scoping known good signals. Once you get a grasp of what is good then you should be able to spot a bad.During this learning period my aim is firstly to understand what I see happening on the screen.
On that vehicle there, you could introduce faults and look for the changes in the waveform. You can lower compression by leaving the hose loose and then manipulate ECT to make it run rich and lean.
However at snap throttle is always a difficult one as so much happens so quickly, not to say it cant be done.
What on that waveform concerns you, I see that you have 3 inductive Pick ups all on the same ht Lead, there will be minor differences ? You are not making a "Metal to Metal" Measurement more picking up a magnetic field after it has left the wire "so to speak" Even on a length of wire with a "Metal to Metal" you would see some Voltage drop (assuming current is flowing). More so with an accurate instrument such as Pico. We now digress into Voltage Drop, that is another story.