PicoScope 7 Automotive
Available for Windows, Mac, and Linux, the next evolution of our diagnostic scope software is now available.
Camshaft Position Sensor :
Camshaft Position Sensor :
Hello you all !
Could someone please tell me :
- why does each sequence start with a peak higher than the others?
- is it possible to see the the "top dead spots" ?
- Here there are three different sequences: I am surprised because from what I know, in most cases, a single sequence is enough to fill the calculator. Do you have any explanation ?
(2 strokes engine, Mercury Optimax fuel injection)
thanks a lot !
Nico
Could someone please tell me :
- why does each sequence start with a peak higher than the others?
- is it possible to see the the "top dead spots" ?
- Here there are three different sequences: I am surprised because from what I know, in most cases, a single sequence is enough to fill the calculator. Do you have any explanation ?
(2 strokes engine, Mercury Optimax fuel injection)
thanks a lot !
Nico
- Attachments
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Re: Camshaft Position Sensor :
Well, I just found the answer for those who care. The current variations observed on the oscilloscope are due to variations in the magnetic field inside the sensor. The disturbance is maximum when a tooth approaches (positive peaks), and when the tooth moves away (negative peak). When a tooth is missing, the duration of the disturbance increases, increasing both negative and positive intensities.
So, on my graph, three different areas are used (missing three times, one tooth) : I don’t know why (usually only one is enough as a marker for the calculator). I think there is one mark per cylinder because it is a three cylinder engine.
Can anyone confirm this hypothesis?
Thank you!!
So, on my graph, three different areas are used (missing three times, one tooth) : I don’t know why (usually only one is enough as a marker for the calculator). I think there is one mark per cylinder because it is a three cylinder engine.
Can anyone confirm this hypothesis?
Thank you!!
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ben.martins
- Pico Staff Member
- Posts: 545
- Joined: Tue May 16, 2017 1:02 pm
Re: Camshaft Position Sensor :
Hello zebraone,
Apologies for only getting back to you on this and thank you for posting your reply.
This is something I've seen before on a marine engine (Mercury Mariner V6, 2 stroke)
Being a two stroke there is no need for a camshaft which means for direct injection and ignition packs the ECU needs to know the position of the engine. Typically there will also be a MAP sensor which can help with engine stroke position but for more precise control, it needs to know where the crankshaft is in relation to the compression stroke. My understanding is that the additional notches on the crank pick up is so the ECU can identify the cylinders. This is something that I think Honda used as well.
I don't have any evidence to back this up though and hopefully someone can back this up.
Great to see some alternative applications of the scope!
Kind regards
Ben
Apologies for only getting back to you on this and thank you for posting your reply.
This is something I've seen before on a marine engine (Mercury Mariner V6, 2 stroke)
I don't have any evidence to back this up though and hopefully someone can back this up.
Great to see some alternative applications of the scope!
Kind regards
Ben
- Attachments
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- Mercury_Mariner_2001_Petrol new battery at starter and engine with startup running 1 buffer.psdata
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