Tuning Tasks

  1. Check original base tune setting for CLT thermistor setting. I messed around with this when my CLT sensor was stuck at the failsafe value of 180F. Turns out I had a broken wire in a butt splice underneath some heat shrink that I repaired. So which is it, Mazda or RX-7 S4&S5?
  2. Figure out why MS3 is not reading NB cam sensor. Could be bad sensor or bad wiring between sensor and CAS harness. According to Reverant, the MS Labs MS3 needs no adjustment to fix this. Maybe it has a circuit that automatically adjusts sensor input sensitivity or gain? Regardless, I’m unsure whether there is a potentiometer on the PCB to adjust like with other MS3. Definitely keep Cam Input set to JS10.
  3. Once NB cam sensor is verified to be working, perform Composite Log to verify cam signal is syncing with crank signal. This is only necessary in the future if I switch to sequential fuel injection and/or VVT control. Right now the engine can run off the crank position signal alone as the software can then interpolate the cam position.
  4. Update ignition coil cranking dwell and running dwell. Everybody seems to have a preference for dwell settings. My base tune came with settings that are different than what DIYAutoTune recommends for the stock Miata ignition system. Cranking dwell from 6ms to 8ms, running dwell from 3ms to 5ms per DIYAutoTune instructions How to MegaSquirt Your Mazda Miata > Dwell settings for 1.6 liter coils in the 1990-1993 cars. Not sure how important this is or if I should actually change it.
  5. Setup automatic data logging thresholds. Automatically start anytime engine is started and rpm >500, set max file size and max time duration. This way I won’t miss critical information.
  6. Adjust the tune by adding fuel so that the engine doesn’t go full lean as soon as I step on the accelerator pedal when free-revving the engine with no load. Once I can free-rev the engine with no load and hit target AFRs then I can begin to think about auto-tuning using VEAL.

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