99 miata (bored to) 1.9l, BW EFR 6258 running about 10lbs of boost for 245whp on AEM ems4. ATI harmonic damper with 12+1 trigger wheel. 800cc injectors, 190 high pressure fuel pump on pump gas.

After finally getting my car all sorted out/tuned and finally able to drive it (yay) we were getting a pretty consistent error count on the cam signal. My AEM ems4 is being told to only read 2 teeth on the cams even though there are 3, two are too close together for it to differentiate 95% of the time. But I believe that sometimes it catches the 3rd tooth and that's what could be causing this cut-out.

I read using an evo 8 cam sensor (mag) and changing the ecu to read falling signal instead of rising can help the issue, I tried it and it did help, so instead of a consistent error count it is much less common/more sparatic.

It's a quick blip like cut out which it likes to do at idle and consistent highway speeds. Sometimes while doing a pull, which is much more noticeable when it cuts, but its only done that maybe 2-3 times while idle/highway it does it maybe once every couple minutes. Other times its fine, its very random.

Should I cut 1 or even 2 teeth off the cam gear and tell AEM that its 12 and 1, which AEM prefers anyway?
Any other ideas on how to fix this or possibly what else might be causing it?

 

Darby you might want to post this on the AEM section under ECU's

 

I'm also on a boosted EMS4 and had a similar issue. Solution was shaving off one tooth from the sensor and going with 12+1 crank trigger wheel.

Any issues with the IACV pushing noise into the cam/crank signals? I needed an isolation circuit.

 

Which tooth did you grind off? I am also having problems with my IACV but im not sure if its giving them noise or not, it just doesn't really like to idle and will stall out after first start up if I don't rev it.

 

Responded in the AEM section. You do not grind off cam gear teeth.