Second optoisolator on MS2
02-27-2013, 08:39 PM
#21
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The CD40106 itself has a considerable internal hysteresis. It also guarantees nice, sharp output waveforms, and because it is a voltage-mode device, we can construct rather generous low-pass filters on the inputs to further defeat any incoming noise. (In the schematic, R121 and C120 are the filter on the crank signal, R126 and C125 are the filter on the cam signal.)
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02-27-2013, 09:24 PM
#22
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Under the diagnostics tab.
You're chasing your tail if you haven't taken a composite log first. It will show you (if) you have a sync problem, and if so, which sensor is not coming through.
I am generally amazed at when I see a report of a sync problem on a Miata. I personally have numerous Miata installs under my belt, as in I can't count/remember them all, and have never had a sync problem. As a company, Miata is one of our top selling applications, and I don't recall any sync problems with any of our prebuilt units if correctly installed.
You're chasing your tail if you haven't taken a composite log first. It will show you (if) you have a sync problem, and if so, which sensor is not coming through.
I am generally amazed at when I see a report of a sync problem on a Miata. I personally have numerous Miata installs under my belt, as in I can't count/remember them all, and have never had a sync problem. As a company, Miata is one of our top selling applications, and I don't recall any sync problems with any of our prebuilt units if correctly installed.
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02-28-2013, 09:42 AM
#25
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Also, DON'T run a datalog while running the composite log. They compete for bandwith and I want all resolution in the composite log possible.
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02-28-2013, 10:20 AM
#27
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I tried really hard several years ago when I was doing the initial install on my '92. Wound up saying "**** it" and building a 36-1 crankwheel setup. (This was, admittedly, a rather disproportionate response to the situation.)
The 40106 solution has excellent filtering and hysteresis, and doesn't rely upon current-mode devices which offend my sensibilities.
The 40106 solution has excellent filtering and hysteresis, and doesn't rely upon current-mode devices which offend my sensibilities.
I've never had a single issue with any local installs, and from what customers are telling me, no problems on customers' cars either.
I do not consider the optoisolator input a flawed design or implementation, since it works 100% correct in every single car.
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02-28-2013, 11:07 AM
#29
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And what exactly did you try?
I've never had a single issue with any local installs, and from what customers are telling me, no problems on customers' cars either.
I do not consider the optoisolator input a flawed design or implementation, since it works 100% correct in every single car.
I've never had a single issue with any local installs, and from what customers are telling me, no problems on customers' cars either.
I do not consider the optoisolator input a flawed design or implementation, since it works 100% correct in every single car.
We have over 1000 Miata MSPNPs in the hands of consumers, and no reports of sync problems that were MSPNP hardware problems. I do not know how many several thousand more Miatas are running other MegaSquirt based products, but it is in the thousands.
I have seen other issues. These cars are hitting 20 years old, and some of the CAS's are starting to fail, as are wiring harnesses and connectors. Can't fault the ECU for mechanical problems.
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02-28-2013, 11:19 AM
#31
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<edit>
I take that back. When I zoom out on the 1st page of this file, there are 2 dropouts of the CMP signal.
The CMP signal is not tricky to read. I would suspect a bad CAS or wiring fault before the hardware conditioner.
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02-28-2013, 08:03 PM
#37
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Unless the 20 year old wiring is broken.I saw in the composite log that CMP is missing, and posted it below. Note that there was an edit in my earlier post, as the dropping CMP signal was hidden at first.
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03-01-2013, 03:19 AM
#38
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I have probably used 5 or 6 different tach input conditioning circuits that *all* work perfectly for this application, from the optoisolator as found on V3.0/3.57 PCBs to the MAX9926 as found on MS3-Pro.
We have over 1000 Miata MSPNPs in the hands of consumers, and no reports of sync problems that were MSPNP hardware problems. I do not know how many several thousand more Miatas are running other MegaSquirt based products, but it is in the thousands.
I have seen other issues. These cars are hitting 20 years old, and some of the CAS's are starting to fail, as are wiring harnesses and connectors. Can't fault the ECU for mechanical problems.
We have over 1000 Miata MSPNPs in the hands of consumers, and no reports of sync problems that were MSPNP hardware problems. I do not know how many several thousand more Miatas are running other MegaSquirt based products, but it is in the thousands.
I have seen other issues. These cars are hitting 20 years old, and some of the CAS's are starting to fail, as are wiring harnesses and connectors. Can't fault the ECU for mechanical problems.
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03-04-2013, 03:34 PM
#40
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