My stock 04 doesn't have a MAP sensor; and only (1) IAT sensor.

No stock Miata had a MAP sensor. (Well, the MSMs might have- I'm not sure. But it's irrelevant.) The Megasquirt comes with a MAP sensor, and for most applications, this is used as the primary load input. No need for MAF.

you only need (1) ait sensor, and the MS comes with its own (1) map sensor


seriously, stop posting, start reading. This is like 2+2

Answers my questions. Thanks guys.

Oh, Vlad, you really don't need a turbo, you need to get blown.

Oh, this should be funny :drama:

that's what the turbo is for...

Sure thing. I'll be right over. You must give amazing head, seeing that you don't have enough brain power to do anything else, like research what a Megasquirt is and does, and what your car needs to effectively run a mediocre small turbo setup properly

Not a miata, but a few Eunos Roadsters had them, they were fitted directly to the ECU, I ASSume for barometric correction?!

Also my MK2.5 MX-5 has a 'boost' sensor, again I ASSume this is a map sensor for barometric correction - albeit in the engine bay this time.

Although I am confused as to why a MAF equipped car woul need such a correction.

I digress however, this is not really relevant to the OP. OP you should buy a Reverant MS, you can't beat it for the price.

the boost sensor is for the EGR if I recall correctly.

^ That.

All of the NBs had what you could call a MAP sensor, however it was used solely to validate the operation of the EGR system, and throw a CEL if it determines that the operation of the EGR valve (while in a diagnostic cycle) is not producing the expected fluctuations in pressure at the test point.

This sensor is NOT used in the primary fueling calculation, it is simply there to help you fail an emissions test.

The '90-'93 cars did have a barometric pressure sensor (inside the ECU case) which was used as a correction on the volumetric airflow sensor.

Getting back on point, although it is capable of operating in MAF or alpha-N mode, most Megasquirts use MAP as the primary load input. Thus, all* Megasquirts include a MAP sensor on-board.

* = There are certain "specialty" Megasquirt products such as the MS3Pro and the MicroSquirt which do not have the MAP sensor on-board, but rather require that you install an external MAP sensor. This is purely a packaging consideration- they function the same as the regular Megasquirts with regard to the load computation.

The "EGR boost sensor" on my 2002 is clearly a baro sensor, since the MAP is hanging in free air and not connected to the intake or anything.

I was about to reply asking if my 'boost sensor' should therefore be plugged into the intake plenum, I guess not :)

Makes sense now that you clarified it Joe that some of the the early 1.6's had a barometric MAP sensor, they're not MAF equipped, only AFM equipped!

I guess that means an EGR pipe delete to the turbo manifold would produce a CEL.

of course it would.

??

That sensor is supposed to have a hose on it which connects to a port on the intake manifold.

This is how the ECU checks for the operation of the EGR system. It waits until the vehicle is warmed up and in decel, then it pulses the EGR valve itself open/closed and looks for a corresponding change in the reading of the sensor. This change was implemented (in north America, anyway) in 1999, when the EGR syste changed from a vacuum-operated valve to a six-wire stepper motor.

Or were you merely pointing out that you have re-purposed the sensor in your car after having removed the stock ECU?

IIRC there are two.

IIRC, there is one, with a two-way solenoid between it and the manifold. The solenoid exposes the sensor to atmo as a reference, and then switches it to the manifold for the functional test.

There is absolutely no EGR map sensor on my car that is connected to the intake manifold. Same goes for every 01-05 1.6/1.8 Miata here in Greece. Maybe its a EUDM thing.

The "HITACHI BOOST SENSOR" that is above the passenger side wheel is reading free air. Its clearly a baro sensor.

yeah, I think I was confusing the EGR Boost Sensor Solenoid, for a second sensor.

anyways, it references the exhaust flow back into the intake.

https://www.miataturbo.net/attachmen...1&d=1355329431