Cummins/Onan QST30-G3 Generator Set

⚠ Make sure there is no grease or dirt on the ECM mounting surfaces. Properly tighten the 6 capscrews per the capscrew size/grade torque recommendations to prevent mounting failures.

1. Determine the location for the ECM; ensure sufficient clearance for the wiring harnesses.
2. Use all 6 mounting holes; machine and tap, or drill thru clearance holes for capscrews and nuts.
3. Tighten the 6 capscrews per the capscrew size/grade torque recommendations.
4. Do not mount the ECM directly to the engine block or any engine block component without proper thermal and/or vibratory isolation.
5. Mount the ECM up to 15.2 m [50 ft] total harness length from the engine harness at the flywheel housing.

⚠ Jam nut over-torque will damage the magnetic pickup.

Tools: Feeler gauge

1. Remove the pipe plug on the right-hand side of the flywheel housing.
2. Ensure that a ring gear tooth is centered under the magnetic pickup hole; rotate the flywheel if necessary.
3. Screw the magnetic pickup in until it contacts the targeted gear tooth; do not use excessive pressure.
4. Back the magnetic pickup out (counterclockwise) 1/2 to 3/4 turn.
5. If a feeler gauge fits between pickup and tooth, back out 0.71 to 1.07 mm [0.028 to 0.042 in.].
6. Tighten the jam nut on the flywheel housing while holding the magnetic pickup.
7. Torque the jam nut to 34-47 N-m [25-35 ft-lb].
8. Plug the electrical connection into the magnetic pickup, when required.
9. Install the main generator, if it was removed.

⚠ The pressure of the fuel in the line is sufficient to penetrate the skin and cause serious bodily harm. Carefully loosen the fittings and wear hand protection.

⚠ Do not engage the starter for more than 30 seconds each time when venting the system. Wait 2 minutes between engagements.

Tools: Hand protection

1. Low pressure lines: loosen the fuel filter head pressure relief banjo fittings (1) on top of the fuel filter head.
2. Operate the plungers (2) on the fuel lift pumps until fuel flowing from the pressure relief fittings is free of air.
3. Tighten the banjo fittings (1); torque 8.8 N-m [6.5 ft-lb].
4. Pump(s): loosen the fuel pump galley outlet line banjo fitting(s) (3).
5. Energize the Fuel Pump Shutoff Valves (24VDC) and operate the lift pump plunger, or crank the engine, until fuel bleeds from the line.
6. Tighten the fuel pump galley outlet line banjo fitting(s) (3); torque 23 N-m [17 ft-lb].
7. High pressure lines: loosen the fittings at the injectors; crank the engine to bleed trapped air; tighten the fittings.
8. Start the engine, and after it starts vent one line at a time until the engine runs smoothly.

1. Complete the following steps after each oil change or after the engine has been shut off for more than 120 hours.
2. Disconnect the multi-pin cable from both fuel pumps.
3. Rotate the crankshaft, using the starting motor, until oil pressure appears on the gauge or the warning light goes out.
4. Reconnect the multi-pin cable to both fuel pumps.
5. Start the engine.

1. Allow the engine to idle three to five minutes after a full load operation before shutting it off.
2. This allows the engine to cool gradually and uniformly.

⚠ Do not idle the engine for excessively long periods; more than 10 minutes can cause carbon buildup, clogged injector spray holes and sticking valves.

1. Start the engine with the IDLE/RUN switch (using the idle feature) in the idle position.
2. Do not engage the starting motor more than 30 seconds; wait two minutes between each start attempt.
3. Engine oil pressure must be indicated on the gauge within 15 seconds; shut off immediately if none.
4. Idle the engine three to five minutes between 700 and 900 RPM before switching to Rated Speed RPM.
5. When starting a cold engine, increase engine speed slowly from Idle to Rated Speed.
6. Do not idle the engine for excessively long periods; long periods of idling, more than 10 minutes, can damage an engine.

⚠ Severe damage to the fuel pump will occur unless the fuel pump is unlocked prior to operation.

1. Rotate the engine slowly clockwise to align the timing mark on the crankshaft damper with the timing pointer; ensure #1 cylinder (right bank) is on the compression stroke.
2. Remove the timing pin cap and verify that the pump is locked.
3. Install the timing pin (1), cap (2) and sealing washer (3); torque to 30 N-m [22 ft-lb].
4. Set the in-line fuel injection pump assembly in position at an angle with the bracket partially installed.
5. Tighten the four injection pump bracket mounting bolts (2) and four pump mounting bolts (4); torque 66 N-m [49 ft-lb].
6. Tighten the coupling bolts (1); torque 108 N-m [80 ft-lb].
7. Install the high pressure fuel lines (3); torque 24 N-m [17 ft-lb].
8. Install the fuel pump drain line and fuel return tube (2); torque 9 N-m [80 in-lb].
9. Install the injection pump drive shaft cover (1).
10. Install the low pressure fuel lines (2); torque 24 N-m [17 ft-lb].
11. Install the oil lines (3); torque 27 N-m [20 ft-lb].
12. Install the electrical connection (1).
13. Unlock the fuel pump timing prior to operation.

⚠ If the pump does not align, do NOT force the pump and driveshaft into alignment. Forcing will result in fuel pump damage.

⚠ Severe damage to the fuel pump WILL occur unless the fuel pump is unlocked prior to operation.

Tools: Standard 3 jaw puller kit

1. Rotate the engine slowly clockwise to align the timing mark on the crankshaft damper with the timing pointer; ensure #1 cylinder (right bank) is on the compression stroke.
2. Remove the timing pin cap and verify that the pump is locked.
3. Install the timing pin (1), cap (2) and sealing washer (3); torque to 30 N-m [22 ft-lb].
4. Install the spline coupling (1) onto the pump driveshaft gear.
5. Engage the spline coupling and install the pump driveshaft gear into the drive housing.
6. If the pump does not align, do NOT force it; align with the front and bottom pump support brackets.
7. Install the four capscrews (1), washers and nuts that mount the pump to the drive housing; torque 66 N-m [49 ft-lb].
8. Install the two front injection pump bracket mounting capscrews (1).
9. Install the two bottom injection pump bracket mounting capscrews (2); torque 66 N-m [49 ft-lb].
10. Install the low pressure fuel lines (2); torque 24 N-m [17 ft-lb]. Install the electrical connection (1). Install the high pressure fuel line (2); torque 24 N-m [17 ft-lb]. Install the fuel pump drain
11. Tighten the three visible capscrews in the fuel pump drive gear; torque 115 N-m [84 ft-lb].
12. Unlock the fuel pump timing.
13. Rotate the engine one full revolution; tighten the fourth capscrew to 115 N-m [84 ft-lb].
14. Re-install the cover plate on the front gear cover; torque 65 N-m [48 ft-lb].

Tools: Protective covers

1. Rotate the engine slowly clockwise to align the timing mark on the crankshaft damper with the timing pointer; ensure #1 cylinder (right bank) is on the compression stroke.
2. Lock fuel pump timing by reversing the timing pin in the locked position.
3. Clean debris around the in-line fuel injection pump; disconnect electrical connection (1), low pressure fuel lines (2) and oil lines (3).
4. Remove the injection pump drive shaft cover (1); disconnect fuel pump drain line and fuel return tube (2) and high pressure fuel lines (3).
5. Install protective covers to prevent dirt from entering the discharge ports.
6. Disconnect the coupling bolts (1).
7. Loosen the four injection pump bracket mounting bolts (2).
8. Remove the injection pump and bracket (3) at an angle as one unit.
9. Separate the fuel pump from the bracket by removing the mounting bolts (4).

1. Clean the debris from around the fuel pump timing pin cap.
2. Remove cap (2), sealing washer (3) and timing pin (1).
3. Reverse the timing pin and re-install in the locked position.
4. Install cap and sealing washer. Torque cap to 30 N-m [22 ft-lb].

⚠ Severe damage to the fuel pump will occur unless the fuel pump is unlocked prior to operation.

1. Remove the fuel pump timing pin cap (2), sealing washer (3) and timing pin (1).
2. Reverse the timing pin and re-install in the unlocked position.
3. Install cap and sealing washer. Torque cap to 30 N-m [22 ft-lb].