Mostly good stuff, I am gaining a fresh interest as I am fighting a serious, ocassional lurch now.
I've verified the polarity of the signals with an oscope.
The signals are both getting flipped here, this is with my old circuit. It's also really noisy, again, an old issue.
I've been trying to get verification from another source but as of yet have found none.
I'm very sure on my advice of checking sensor gap, as well.
When I moved the sensor closer, this "sticking" went away. I've seen this same effect in several different, unrelated, cars. Some MS, some AEM, just around the web. I don't think there's some magic way an opto-isolator will take bad data and turn it good. Not trying to sound smug here, but I don't think it's (yet) the issue.
I'm quite curious about this opto-isolator input, and have some questions:
Looking at the input side of the circuit, I see this:
Which tells me that they are all the same. Except that one is opto isolated (except all my noise tends to head towards ground, so I don't think that's the issue) and that the circuit has
1/100th the capacitance of what I've already got.
If I'm over simplifying the optoisolator, let me know. As I understand it, from the outside world, it's a black box that acts like an NPN with the input being as the base.
Now, the filter on the output I *do* like, only I don't really expect the transistor to output noise if it doesn't get it in. And from some of my traces, I already have evidence of that, noisy input and clean output.
I *really* do appreciate the suggestion, so forgive me if I'm giving it a brutal analysis - I'm hoping when next I touch iron to board it's with a firm idea of what I want to do. Please keep them coming!
For referance, my car has been running this:
for a week. There's it seems like it's missing a tooth now and then on the crank - but it's a noise issue I think, not what Pat's experiencing. I had exactly what he is having and that was sensor placement. It would be a lot easier to troubleshoot with a scope (for instance to know if his sensors are inverted relative to each other as mine are).
My only *other* suggestion is to build another non-inverting ("crank"-type) input, use it for the cam, and see if it magically runs. My guess is no.