RX7 FC CAS Setup | AEM
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styx1234
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Joined: 05/10/2020 - 19:45
RX7 FC CAS Setup

I just finished installing an Infinity 506 into an FC RX7 using the factory CAS. I have the 12 tooth Crank VR + and - pinned to pin 17 and 18 respectivly. The 1 tooth Cam VR + and - are pinned to 20 and 19 which I think is correct. In the setup wizard, selecting the mazda rotary CAS deaults to the 12 mag crank, 1 mag cam. Everything seems to check out but I'm not getting any RPM or crank angle reading when I crank the car. I've checked the 4 wires going to the CAS for shorts and continutity and cant find anything wrong.

I'm getting readings from all my other sensors. I have a sequential coil on plug setup. I know the CAS is functional since I had the car running on the stock ECU before I tore into it.

I've tried playing with the noise cancelation values with no luck. Am I missing anything setup related?

My SparkProbablity anf InjectorProbability are both 100% but my SyncState and Start Probablity ar 0.

 

Any help would be appriciated. Thanks!

AEM_NS
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Joined: 06/06/2014 - 09:31
Would be helpful if you

Would be helpful if you provided a log showing the engine being cranked over for ~10 seconds.

styx1234
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Joined: 05/10/2020 - 19:45
Here is the log. Pretty much

Here is the log. Pretty much everything is flat because it won't pick up engine RPM.

 

Log 1.itssn

Log 1.itlog

David Back

AEM_NS
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Huh I would have thought you

Huh I would have thought you were at least getting some crank/cam durations but you're getting nothing. Probably a good idea to check the signals with an oscilloscope. You can also try decreasing the 0 rpm VR PwmDuty value. This sets the VR trigger threshold voltage. Trying turning it down to 10 to see if the signal starts getting picked up.

styx1234
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Joined: 05/10/2020 - 19:45
Turning the VR PwmDuty down

Turning the VR PwmDuty down to 10 did the trick! It started right up and idled. Thanks for the help.

Is this indicative of a larger issue like a weak signal or too much noise? I'm going to try to incrementally increase the VR PwmDuty value until I find the point where it won't read, but will I have problems in the future if that value is too low?

David Back

AEM_NS
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Last seen: 3 hours 42 min ago
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Well the signal is going to

Well the signal is going to have whatever amplitude it's going to have. The key is to try and keep the trigger threshold as high as possible to try and ignore lower amplitude noise so yes, it'd be a good idea to find the go/no-go threshold and then operate just below that point. Remember the VR signal amplitude increases with RPM so when cranking, it isn't uncommon that the signal be very low. Since this is only for cranking, having it low is okay. You'll also have to do the same thing for the 500 rpm value. Keep it as high as possible without inducing problems.