Mazda Rotary Club

Cars by Model Type => 3rd generation RX-7's => Topic started by: rx7boy on April 05, 2012, 12:30:36 AM

Title: MAP sensor help
Post by: rx7boy on April 05, 2012, 12:30:36 AM
Was just about to fire Kimi\'s car up after all the intake work that\'s been done to it and noticed that once I turned the ignition on the commander showed the boost/vacuum as being -35.

I thought this was slightly odd and was unsure that the reading should be 0, so I swapped out the sensor for another unit and again same -35, just to be extra safe checked it against a third map sensor and
It gave me -36. So I can rule out the sensor. I then checked the 5v feed line and it was giving a solid 5v.

So need some help if in figuring out why the reading isn\'t 0. One thing did spring to mind is that where the unit is has very high pressure as its on top of a hill, does this effect the map sensor reading ?

I\'m probably worrying to much but as its Kimi\'s car I would rather be safe than sorry. Will be back there tomorrow checking all earths as this has been suggested. Also the sensors and corresponding values change when adding pressure via a pump.

So essentially need someone to tell me if the map sensor if effected by atmospheric pressure. ??
And what their FD map sensor reading is at ignition on ??
Title: MAP sensor help
Post by: philiwily on April 05, 2012, 02:06:21 AM
It\'s nothing to worry about, it\'s not the map sensor, it\'s the PIM map reference table in the PFC is slightly out as standard.
It can be adjusted to real life pressure using a dataloggit but it\'s time consuming and only really necessary if you want all your boost gauges to read the same.
Changing it would also disrupt your map.
It is also affected by atmospheric pressure.
Title: MAP sensor help
Post by: rx7boy on April 05, 2012, 02:34:23 AM
Quote from: philiwily;818773It\'s nothing to worry about, it\'s not the map sensor, it\'s the PIM map reference table in the PFC is slightly out as standard.
It can be adjusted to real life pressure using a dataloggit but it\'s time consuming and only really necessary if you want all your boost gauges to read the same.
Changing it would also disrupt your map.
It is also affected by atmospheric pressure.

You sir are a legend, have spent the last 3 hours looking for that exact answer. Next event I owe u a beer :cheers
Title: MAP sensor help
Post by: philiwily on April 05, 2012, 10:35:35 AM
:cheers Mmm Beer