Hummer H1 (1992-1998). Manual - part 43

2-140.20          Change 1

2 - 3 5 . 3 . (6.2L or 6.5L)  FUEL INJECTION PUMPS (DB2829-4523, DB2829-4879, or

DB2831-5149) CALIBRATION USING FUEL INJECTION PUMP TEST STA N D

(FTIS) MODEL A8022 (Cont’d)

9.

If transfer pump pressure does not read 70-76 psi (483-524 kPa), decrease pump speed to 0 rpm and
turn off main drive and calibration fluid systems. Disconnect hose at hydraulic head fuel inlet port.

10.

Adjust transfer pump pressure with 74-1137 5/32-in. Allen screw-driver (74-8032 adapter kit, slot 3,
or equivalent) and reconnect hose. This pressure setting is critical.  Repeat test and adjust until
transfer pump pressure is within limits.

11.

Check pump return flow. With pump speed at 1000 rpm WOT, pump return flow meter should read
225-375 cc/minute. Perform adjustment if necessary.

12.

Reduce pump speed to 325 rpm. Move throttle lever to LOW IDLE position and secure. The average
flow reading on CRT monitor should be 10-18 mm

3

/

stroke. If flow is not correct, adjust low-idle screw

or MIN-MAX governor setting to obtain proper flow.

13.

With pump speed still at 325 rpm, and throttle lever secured in low-idle position, check/adjust
variable DC voltage to 17.6 volts as follows:
(a) Connect positive red test lead to cold-advance solenoid terminal. Housing pressure reading on

CRT monitor should be 0-1 psi (0-7 kPa).

(b) Disconnect positive red test lead from cold-advance solenoid terminal. Reduce variable DC

voltage to 0 volts. Reconnect red test lead to shutoff solenoid terminal. Reduce pump speed to
200 rpm.

(c) Slowly increase variable DC voltage and note voltage at which time the solenoid pulls in by

listening for a clicking sound from the shutoff solenoid. (That indicates proper operation.) The
shutoff solenoid should pull in with a maximum of 17.6 volts applied.

14.

Reduce pump speed to 75 rpm. Move throttle lever to WOT position and secure. Average flow
reading on CRT monitor must be a minimum of 28 mm

3

/stroke.

15.

Increase pump speed to 200 rpm with throttle lever secured in WOT position. Average flow reading
on CRT monitor must be a minimum of 47 mm

3

/stroke. Disconnect positive red test lead from

solenoid shutoff terminal. The average flow reading on CRT monitor must be 4 mm

3

/stroke

maximum. Reconnect positive red test lead to shutoff solenoid terminal.

16.

Increase pump speed to 325 rpm. Move throttle lever to LOW IDLE position and secure. Average flow
reading on CRT monitor should be 10-18 mm

3

/stroke with a minimum of 1.5 degree cam movement on

advance indicator. Connect positive red test lead to cold-advance solenoid terminal.  Housing pressure
reading on CRT monitor should be 0-1 psi (0-7 kPa) with a minimum of 2.75 degree cam movement on
advance indicator. Reconnect positive red test lead to shutoff solenoid terminal.

17.

Increase pump speed to 750 rpm. Adjust throttle lever to obtain average flow reading on CRT
monitor of 21.5-23.5 mm

3

/stroke and secure throttle lever. Advance indicator should have 2.25-

4.75 degree cam movement.

18.

Increase pump speed to 1000 rpm. Move and secure throttle lever in WOT position. Average flow
reading on CRT monitor should be 51.0-55.0 mm

3

/stroke with 0.5-2.5 degree cam movement on

advance indicator.

19.

Increase pump speed to 1600 rpm and ensure throttle lever is secured in WOT position. There
should be 4.25-7.25 degree cam movement on advance indicator. Move throttle lever to LOW IDLE
position. There must be a maximum of 10.0 degree cam movement on advance indicator. Move and
secure throttle lever in WOT position.

20.

Increase pump speed to 1800 rpm and ensure throttle lever is secured in WOT position. Average
flow reading on CRT monitor must be a minimum of 44.5 mm

3

/stroke.

21.

Increase pump speed to 1950 rpm and ensure throttle lever is secured in WOT position. Average
flow reading on CRT monitor must be a minimum of 42.5 mm

3

/stroke.

22.

Increase pump speed to 2100 rpm and ensure throttle lever is secured in WOT position. Average
flow reading on CRT monitor must be a maximum of 8 mm

3

/stroke. Transfer pump pressure reading

on CRT monitor must be a maximum of 135 psi (931 kPa).

Change 1          2-140.21

2 - 3 5 . 3 . (6.2L or 6.5L)  FUEL INJECTION PUMPS (DB2829-4523, DB2829-4879, or

DB2831-5149) CALIBRATION USING FUEL INJECTION PUMP TEST STA N D

(FTIS) MODEL A8022 (Cont’d)

23.

Reduce pump speed to 0 rpm and secure test stand. If pump met specifications, remove from test
stand and mount in holding fixture. If pump did not meet specifications, repair as necessary and
proceed to calibration instructions.

24.

Using air timing gauge, check pump timing. Set timing to -0.75 to +1.25 degree.

25.

Shut down test stand as follows:
(a) Main drive pushbutton OFF.
(b) Lube pushbutton OFF.
(c) Calibration fluid pushbutton OFF.
(d) DC selector OFF.
(e) Master power switch OFF.

c.

Removal of Fuel Injection Pump from Test Stand

1.

Disconnect black test lead from DC black socket marked “P” on test stand (5), and remove alligator
clip end of black test lead from ground terminal (4) on fuel injection pump (3).

2.

Disconnect positive red test lead from DC power supply socket (1) marked (+) on test stand (5), and
remove alligator clip end of red test lead from electric shutoff solenoid terminal (2) on fuel injection
pump (3).

1

2

3

4

5

DC BLACK SOCKET

BLACK TEST LEAD

POSITIVE RED TEST LEAD

2-140.22          Change 1

2 - 3 5 . 3 . (6.2L or 6.5L)  FUEL INJECTION PUMPS (DB2829-4523, DB2829-4879, or

DB2831-5149) CALIBRATION USING FUEL INJECTION PUMP TEST STA N D

(FTIS) MODEL A8022 (Cont’d)

3.

Remove rubber hose assembly from quick-connect on advance indicator block and auxiliary pressure
quick-connect on front panel of test stand (2).

4.

Remove quick-connect from advance indicator block and install screw plug (1) into advance indicator
block.

5.

Remove two screws (7) and advance indicator from fuel injection pump (4), and install gasket (5) and
timing cover (6) on fuel injection pump (4) with two screws (7). 

6.

Remove throttle arm positioner assembly from bedplate (8) and disconnect from throttle lever (3) on
fuel injection pump (4).

CAUTION

When removing high-pressure delivery lines from fuel injection
pump, use two wrenches to protect discharge fittings.

7.

Remove eight high-pressure delivery lines from discharge fittings (9) on fuel injection pump (4).

2

AUXILIARY PRESSURE QUICK-CONNECT

QUICK-CONNECT

RUBBER 

HOSE

ASSEMBLY

ADVANCE

INDICATOR

BLOCK

1

Change 1          2-140.23

2 - 3 5 . 3 . (6.2L or 6.5L)  FUEL INJECTION PUMPS (DB2829-4523, DB2829-4879, or

DB2831-5149) CALIBRATION USING FUEL INJECTION PUMP TEST STA N D

(FTIS) MODEL A8022 (Cont’d)

ADVANCE INDICATOR 

HIGH-PRESSURE

DELIVERY LINE

THROTTLE ARM
POSITIONER
ASSEMBLY

5

6

7

7

4

3

4

9

8