Right then. I have been playing some more with these bloomin cam sensors & I have stumbled across a way of capturing something on a running engine. I didn’t think it would be possible to view the tiny detail in a useful scale, but here is a capture that shows the phase shift area from a zoomed out or "helicopter view" as James Dillon calls it.
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To try to make some sense of this. The red & blue solid colour are the two AC signals, the green trace is the crank sensor signal & the yellow (ish) trace is the secondary ignition from cylinder 2 used as a trigger to hold the image steady.
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To prove that it wasn’t just a fluke "one off" anomaly here is an animation. It clearly shows the cam reference point & seems to confirm the position that I pointed to in my earlier posts.
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Here it is again but this time we are seeing the other end of the phased section. Notice the amplitude of the red trace (thickness of the line). On the first animation the amplitude is less on the left, whereas the second animation has a reduced amplitude on the right.
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I was surprised further by the power of the Pico & the amazing detail. When I froze the screen & zoomed into the area of interest & I scrolled from left to right throughout the capture it became clear that the blue trace remains constant throughout. The red trace is the one that changes in response to the proximity of the cam wheel raised section.
I think it is reasonable to conclude that the blue trace must be the oscillator coil & the red trace is the modulated coil trace.
It looks like I was wrong to state in my first post "ignore the height of the wave" as it looks like an important factor in what the PCM is looking for.
Below are the different phases. Bare in mind that these images are just zoomed in to the previous captures. Nice smooth waves show just how many samples are available with a Pico.
Bloomin marvellous!
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My next mission is to find out what upsets these blighters. I have one coming in soon from the dealers. It has had three new sensors already so I hope to find something useful.
Cheers guys
Dave Hill
on April 6, 2007, 5:13 pm, in reply to "Re: Vauxhall Vecra 2000 X20XEV (Eco Tech Cam Sensor)"