Ricky i run a motorola 3 bar, the scaler for a motorola 3 bar part number 12223861 is 628 and the offset is 0 , you can get them from xenocron here

http://www.xenocron.com/catalog/3-bar-map-sensor-kit-gm-p-195.html. be warned that GM actually makes 3 different 3 bars and each uses a different scaler and offset. the part number i listed above is the one i use.

Here is how to calculate the scalar and offset for a MAP sensor.

1. Find the minimum and maximum voltage and absolute pressures.

2. Convert the pressures to mbar.

3. Subtract the minimum and maximum voltages to find the range, then do the same for the pressures.

4. Divide the pressure range by the voltage range to calculate the scalar.

5. Multiply the minimum voltage by the scalar to calculate the offset. Note that a positive voltage gives a negative offset.

Example for a 3.5 bar MAP sensor:

1. For a 3.5 bar data sheet:

0.5V @ 0 kPa (absolute)

4.5V @ 345 kPa (absolute)

2. 345 kPa = 3450 mbar.

3. Voltage range = 4.0V, pressure range = 3450 mbar.

4. 3450 / 4.0 = 862.5 = scalar

5. 862.5 x 0.5 x -1 = -431.25 = offset

So scalar = 862, offset = -431

Plug in the minimum and maximum voltages to check your work:

0.5V x 862.5 - 431.25 = 0 mbar @ 0.5v

4.5V x 862.5 - 431.25 = 3450 mbar @ 0.5v