Hey folks! Just join the forum as I just grabbed my first Miata a few days ago. Since driving it I was informed by the previous owner that is has a tuned megasquirt ECU. I have no reference but the car does seem pretty quick. However, I’m not really ready for any high performance mods. That said I would like to remove it And replace with the stock ECU that came with the car. I under stand that the fuel injectors need to change as well to the stock ones. But that is as far as I know. I’d like to hear from some Miata veterans on what else may need to be changed or replaced in order to get back some decent gas mileage (I’ve dumped about half a tank in three days). Any help or advice is appreciated.

Thanks!
Curtis

 

Curtis,

A couple of things come to mind.

The stock MAF or AFM may have been removed as well, since they are an airflow restriction. Finding the correct stock ECU may be a pain. There may be other changes hiding from plain view.

When tuned properly, the Megasquirt should give you better fuel economy than stock. It sounds like a little fine tuning may be in order in your idle and cruise fuel and spark maps. If you want to go this route I can give you some pointers and maybe you can have the best of both worlds, economic cruising and the extra power when you push it.

You didn't mention what year your car was or which version of the Megasquirt it might be.

I'm not over here very often so contact me on Miataturbo.net username sixshooter.

***As an aside, half a tank in the land of Miatas is only 4 to 5 gallons so it isn't as bad as you might think.

Steve