INJECTION PUMP CALIBRATION
Following injection pump or governor service and
overhaul, the pump must be recalibrated to establish
correct internal timing, fuel delivery and governor
operation. It is also recommended that pump calibration
be checked on a calibrating stand anytime the injection
pump is removed to perform engine service operations.
OPERATION IT IS NECESSARY THAT
SEQUENCE, AS OUTLINED IN THIS
NOTE: Refer to individual pump calibration charts and
data sheets (at end of this section) for specifications
mentioned throughout this section.
A calibration stand with 10 HP or more is recommended.
Existing stands of 5 HP are acceptable.
When installing the pump on the test stand follow
instructions furnished with the stand.
Figure 1. Pump on Calibration Stand
Calibrating Stand Maintenance
The calibrating stand must be kept in good operating
condition. Maintenance checks and lubrication of test
stand components must be performed periodically to
assure satisfactory results. Calibrating oil must be of the
specified type. Calibrating oil and filter must be changed
regularly. Transfer (supply) pump must maintain
minimum specified pressure since injection pump
calibration depends upon correct supply pump oil
To assure uniform delivery, calibrating stand test nozzles
should be tested for balance (equal delivery) every six
months or whenever 200 pumps have been tested. The
method for balancing the test nozzles is as follows:
Adjust all test nozzles to specified test
nozzle opening pressure. (See Pump
Install an injection pump on calibrating
Perform the "Maximum Fuel Delivery
Check" and record amount of fuel obtained
from No. 1 pumping element.
Install each of the remaining test nozzles in
the No. 1 nozzle position and note delivery
from each nozzle. If necessary, adjust
nozzle opening pressure to obtain same
flow as recorded for nozzle No. 1 (Step c.).
Nozzles must be balanced to within 0.5cm3
per 1000 strokes.
After nozzle balance (uniform delivery) has
been obtained, recheck opening pressure
of all nozzles. If nozzle opening pressure is
not within specified limits (3000 25 psi),
nozzle should be repaired or replaced.
MOUNTING ON STAND
Before mounting the pump on stand, make sure pump
camshaft can be rotated more then 360°. This is
especially important when the pump has been
When installing pump on stand follow instructions with
Printed in United States of America