Hello ,I am using 3-axis +/-3G ADXL335 Analog accelerometer to determine pitch and tilt sensing with 1degree Precision. I have tested it on the small tractor it works fine when the engine is off but as soon as the engine starts the accelerometer shows false readings. I am new to this field so what steps can you suggest to overcome this. currently the ADXL335 ouput is directly coupled to pic. and i am using 3 axis calculations as per AN-1057 .I have used 0.1uF decoupling capacitors with each analog output of accelerometer to ground.