So I’ve been talking with some other Megasquirt users to request help getting into the ball park with my tune, share ideas and help validate my work so far. omgpham and Valvecovergasket were nice enough to share their tunes with me. And Reverant at MS Labs finally responded to my email with some AFR1, VE1 and Spark1 tables that were scaled for TPS. The maps in his original base tune were scaled for kpa, which is completely meaningless for Alpha-N. But he also admitted he’s never tuned an ITB car before and the tables were just best guesses. I can’t […]

Check original base tune setting for CLT thermistor setting. So which is it, Mazda or RX-7 S4&S5? So I read some old posts on Miataturbo.net and Braineack says several times to use RX-7 S4&S5. Every time I go to Tools –> Calibrate Thermistor Tables and set CLT to RX-7 S4&S5 and write it to the controller, when I open it back up again it shows that CLT is set to RX-7_AFM(S5 in AFM). Both Common Sensor Values share the same data tables so I’m thinking this is just a bug in Tuner Studio.   Figure out why MS3 is not […]

Figure out why MS3 is not reading NB cam sensor. Could be bad sensor or bad wiring between sensor and CAS harness. So I think I fixed the cam position sensor (CMP) issue: power and ground were apparently swapped by mistake due to misread wiring diagram (sensor pigtail has three black wires so no help there). I Googled pictures of exemplar 1999-2000 Miata engines and zoomed in on the CMP sensor to verify the OEM wire colors.   Apparently when reading wiring diagrams, the view is as though you’re looking at the back of the connector where the wires go […]

After a 5 year absence the father/son project Miata has once again returned “home” to my garage. Time to get busy tuning the Megasquirt.  

The plan is to tow the Miata from my dad’s house to my house after Thanksgiving so that instead of hibernating in a cold garage all winter long, it can stay cozy and warm in my garage where I can begin the painstaking process of tuning the ECU as time permits. Our winters are generally much more mild and thus more conducive to working on cars. Also, we have a lot more dyno facilities in my area. The goal is to street tune the car. Then once the car is generally drivable and I better understand the ins and outs […]

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? 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 […]