What should the Baro reading be at with engine not running and running. and what does it read from.

 

The MAP sensor reads barometric pressure when the key is on with out the engine running. It normally should read anywhere between 97kpa-100kpa just setting there without the engine running but it depends on altitude, if you were way up in the mountains so many thousand feet up then it may only read in the low 90's. Then once the engine is running the MAP sensor serves it's second and main purpose by reading absolute pressure in the manifold.

At WOT on a naturally aspirated engine it should read pretty close to what it does when the engine is not running as long as you dont have any restrictions on the intake side of things. A low map reading at WOT is a good indicator of a restriction on the intake side of the motor.

Some operating systems have a seperate Barometric Pressure Sensor.

 

Thanks I thought that the Map might read it but wasnt sure and it reads 99kpa so I guess its working.