YDT262 Operating and Servicing Manual
DELPHI DIESEL AFTERMARKET
6
HL018, Issue 2
1. Introduction
The Dynamic Timing Control Box (YDT262) is used to determine the timing position of diesel fuel
injection pumps. It is used in conjunction with a host test bench (to mount and drive the fuel pump), a
rotary encoder (providing angular position information), and a piezo pickup (giving the point of
injection signal).
2. Definition of Terms and Abbreviations
The following terms and abbreviations are used in this manual and/or in the YDT262 software.
SP
Start Position. The box records a reference point for starting position (effectively
0 degrees). This is used later when calculating the Overcheck Angle.
Offset
The angular offset to be applied from the point of injection to the locking position.
Trigger Level
The piezo signal trigger level at which the angular position is recorded.
POI
Point of Injection
RLP
Required Locking Position. This is equal to POI plus/minus the Offset.
Overcheck Angle
The difference between SP and RLP.
3. Principle of Operation
The rotary encoder is mounted on the pump drive coupling and the piezo pickup is connected to one
of the pump delivery valves. The piezo pickup provides a signal once every revolution at the point of
injection. By comparing this signal with the angular position information from the rotary encoder, the
point of injection angle is found.
The actual position is found by taking a number of samples at a given speed. The software then
calculates the average position and, once the drive has been stopped, provides you with an angular
countdown so that you can rotate the pump around to that position.
THIS IS AN UNCONTROLLED DOCUMENT downloaded by Lukas Matuska on 16 Feb 2016
Any technical intervention requires certified Hartridge training. Contact Hartridge Ltd for details.
