Map sensor question

[napkinthief]

what does the map sensor do? i know if it reads boost instead of vacuum there are problems, but what if there was just no hose connected to it?

 

[XMasta19]

manifold absolute pressure sensor...takes reading from the intake manifold. thus when you begin to boost, it sees that and goes crazy ### it's not meant to encounter that.

 

[Blitzeclips]

Yeah, kinda what Xmasta said. It reads positive manifold pressure, if this is abnormal when boosting, your car doesn't respond to the extra air very well, because it wasn't built to read the extra pressure. I'm sure theres a more in depth answer to it but thats the just of it..

 

[DSMcrazy3]

Our cars are non turbo. So pressure in the manifold should not exceed 0. When we add a turbo to our car, and the pressure in the manifold rises to say, 8 psi, the sensor see's that and sends a stronger signal to the ECU. When the ECU see's that, as a safe precaution, it immediately cuts the fuel supply, so that it won't support the added air and aid in possibly blowing the motor.

Of course our motors can withstand 8 PSI, but from the factory, since there is already a turbo version of the 2g Eclipse, they figure, "why would anyone who buys a non turbo eclipse turbo it?" So when the MAP see's that pressure it won't think, "oh, this person turbo'd their car and..well, it's ok" So again, fuel is cut.

Hopefully that helps

 

[napkinthief]

Good info, is the turbo model map sensor the same as the n-t sizewise so they can be swapped, or is my only choice a missing link or an electric FCD. also some people have issues with the missing link, and its about the same price as an electric FCD, which one would be easier to do? chance it with a missing link or just go FCD

also if it just reads the positive pressure, can it just be unplugged?

one more thing, I just looked at it in my car, its all wired up, so I am guessing it deals with voltage, is it possible to alter the voltage thats sent through the wire using a resistor or something to

 

[DSMcrazy3]

Turbo models do not have a MAP sensor, the have MAF(Mass Air Flow) instead.

MAP sensor doesn't only read positive pressure, it reads the pressure changes in the manifold. and sends a voltage signal to the ECU, depending on how weak or stong that signal is, the ECU will be able to make a call on the amount of fuel to be supplied.

If the turbo cars had a MAP sensor, you still couldn't just swap them. The information is in the ECU, the MAP sensor simply sends a signal to the computer. Same signal would be sent with a different MAP sensor.

I would go with the FCD. Get in touch with Paul he just made one for another member here and I'm pretty sure would do the same for you.

FCD does basically what you asked if there was a way to do. You put it inbetween the yellow wire going from the ECU to the MAP sensor. I'm not sure what all is used in the FCD, but there is a resistor.

 

[napkinthief]

who is paul?

 

[DSMcrazy3]

VelocitaPaola