Ford 2003 Mustang Workshop Manual page 43

WOT
The acronym for wide open throttle is WOT.
Tools and Techniques
Electronic Vibration Analyzer (EVA)
The EVA is a hand-held electronic diagnostic tool which will assist in locating the source of
unacceptable vibrations. The vibration sensor can be remotely mounted anywhere in the vehicle for
testing purposes. The unit displays the three most common vibration frequencies and their
corresponding amplitudes simultaneously. A bar graph provides a visual reference of the relative
signal strength (amplitude) of each vibration being displayed and its relative G force. The keypad is
arranged to make the EVA simple to program and use. Some of the functions include the ability to
average readings as well as record, play back and freeze readings. The EVA has a strobe balancing
function that can be used to detect imbalance on rotating components such as a driveshaft or engine
accessories.
Item
1 EVA screen
2 Frequency mode displayed in rpm or Hz
3 Active sensor input (A or B)
4 Current active mode
5 G force indicators or the strongest frequencies in descending strength of each vibration
6 Strength of each vibration
7 Frequency in rpm/Hz of each vibration
The EVA allows for a systematic collection of information that is necessary to accurately diagnose and
repair NVH problems. For the best results, carry out the test as follows:
a. Test drive the vehicle with the vibration sensor inside the vehicle.
b. Place the sensor in the vehicle according to feel.
If the condition is felt through the steering wheel, the source is most likely in the front of
the vehicle.
A vibration that is felt in the seat or floor only will most likely be found in the driveline,
drive axle or rear wheels and tires.
c. Record the readings. Also note when the condition begins, when it reaches maximum intensity,
and if it tends to diminish above/below a certain speed.
Frequencies should be read in the "average" mode.
Description