2-140.4 Change 1
2-35.1. (6.5L) FUEL INJECTION PUMP (DB2831-5209) CALIBRATION (Contd)
Set the throttle lever in correct low-idle position prior to calibration using vacuum valve block
gauge. The low-idle screw must be at 34 ± 2 degrees as measured between vertical centerline of
throttle shaft bushing bore and throttle connection stud.
Flush pump with calibrating oil to remove metal chips and possible contamination.
Before mounting pump on test stand, check driveshaft for freedom of rotation in housing. Pump
should be mounted securely in the appropriate adapter, and the intermediate coupling should be
checked for freedom of movement.
Connect supply and return lines securely.
Install high-pressure injection lines. Use copper gaskets or steel washers where required. Leave fuel
line connections at the pump and nozzles loose.
Apply 17.6 volts to electric shutoff solenoid and operate pump at 1000 rpm (WOT) for 10 minutes to
bring to operating temperature and clear air from system.
Tighten all connections securely. Check connections for leaks while operating.
Set transfer pump pressure at 2000 rpm (WOT) for 60-62 psi (414-427 kPa). Test stand boost should
be set at 5 ± 0.5 psi (34.5 ± 3.4 kPa).
Set return oil flow to 225-375 cc/minute at 2000 rpm (WOT).
Measure housing pressure:
Check housing pressure at 650 rpm. With throttle shaft in low idle position, pressure should
be 8-12 psi (55-83 kPa).
Energize housing pressure cold advance solenoid with 17.6 volts. Housing pressure should be
0-1 psi (0-7 kPa).
With governor cover removed and throttle shaft in low-idle position, set min.-max. governor
assembly for 7-9 mm3/stroke at 650 rpm (fuel reading with cover installed).
If low-idle screw adjustment is required, refer to step 3. Adjust-
ment is ± 1 turn from the point in step 3.
At 650 rpm, adjust low-idle screw for 13-15 mm3/stroke for the remainder of the setting and checking
During and at the completion of all settings, ensure face cam-to-throttle shaft end play measures
0.004-0.006 in. (0.10-0.15 mm) between throttle shaft spacer and housing.
At 3500 rpm (WOT), rotate face cam to its maximum lift position in contact with the cam roller.
Adjust trimmer screw at 3500 rpm (WOT) for 4.25 degrees cam advance and set fuel delivery to
Set guide stud for 46.5 mm3/stroke at 3800 rpm (WOT). Tighten guide stud nut to 80-90 lb-in.
(9-10 Nm) and check dimension from top of nut to top of guide stud for 0.425 in. (10.80 mm)
Set throttle for 21.5-23.5 mm3/stroke at 3200 rpm and rotate face cam to obtain 5.00 degrees cam
Tighten face cam screw to 28-30 lb-in. (3 Nm) and check face cam retention.
Put 0.005-in. (0.127 mm) feeler gauge between throttle shaft mylar washer and housing boss.
Put throttle shaft in idle position. Squeeze throttle shaft and face cam tightly toward each
other and rotate face cam as lower roller rests approximately in middle at lowest step. Tighten
screw to 30 lb-in. (3 Nm) with torx bit and remove feeler gauge.
Set total throttle travel. With throttle in low-idle position, align zero degree mark on protractor
with center of rib on rocker lever. Move throttle to WOT and adjust maximum travel screw to
Any changes to pump or settings after this point will require
retesting of pump, starting with step 12.