BOOM GP 3157454 - Caterpillar

Introduction
Do not perform any procedure that is outlined in this Special Instruction until you read and understand the information that is contained in this document.Data Logs are valuable tools to diagnose the health of common rail fuel systems. It is important that the data logs settings are adjusted to reflect equal values on theY-axis (minimum and maximum) scales. These adjustments allow the correct interpretation of data logs.Adjusting the Common Rail Settings on a Data Log
Illustration 1 g02527456
The above Data Log shows the desired and actual fuel pressure of a C6.6 high-pressure fuel pump. The pump does not appear to be performing to specification. This condition is because the Y-axis scales are not equal for the parameters that are recorded. If the 43437 kPa (6300 psi) line in red (1) is followed across the page to the right, the scale on the right-hand side is 43575 kPa (6320 psi) (2). In order to adjust the scales, select "Settings" (3) at the bottom of the page.
Illustration 2 g02527539
After selecting "Settings", the above box will appear. Readjust the settings so that the "Y Min" (4) values and the "Y Max" (5) values are the same.
Illustration 3 g02527549
A good starting point is to set the "Y Min" (6) values to zero. Both the"Y Max" (7) values can then be adjusted so that the value of the "Y Max" is higher than the highest number that is displayed in the "Y Max" boxes. Typically, this value is rounded up to the next highest hundredths for both settings. In this example, adjust 6274 and 6296 to 6300. After the values are adjusted, select "OK" (8) .
Illustration 4 g02527566
After adjusting the "Y Min" and "Y Max" to be equal ("Y Min" to 0.00 and "Y Max" to 6300), the graphs are both on the same scale. The graph will now show the correct comparison of the pressure settings.