Is a check valve needed to go between the MAP sensor and UIM?
 

I havent been running one there for a while and i was told to put the fuel pulsation dampener there but the fpd is huge. In vacuum diagrams that I've looked at it as tophat check valve thing. I would just go put a check valve there but then the sensor wouldn't be able to sense either negitive or positive depending on which way i put it. So does anyone know what needs to go there and so forth.

Thanks
~Luke

Its actually a small air cleaner element to keep particles out.

Your right, if you put a check valve inline, there would be no pressure difference to regulate.

is it needed though?

It's there to protect the sensor from any non-air elements. I would recommend using it.

Mazda put it there to keep fuel and oil out of the map sensor, Ill keep mine :)

It's actually designed to keep any fluctuations in air delivery stabilized to the map sensor. Much like in a dyno graph where you see minute peaks and valleys in the curve, these items are very sensitive to abrupt changes and since our computers(stock system) is quite slow, it cannot interpolate those changes quickly enough. Therefore, this valve is a buffeting chamber and smoothes the air flow, allowing the map sensor to input steady, smooth signal to the ecu, just like the fuel pulsation damper does for the fuel rail.
Art

stupid q? the arrow is supposed to point down right?

not according to this diagram

the arrow should point away from the map sensor as in this diagram too
https://www.rx7club.com/attachment.p...postid=2836901

Interesting... i've never heard this before. What about those of us on standalone computers that use a higher bit-rate? Since the ECU can interpret more signals at a faster rate, would there be any benifit to removing this? I doubt it would make any noticible difference, but it provides for an interesting thought...

Rob