Generac Power Systems 8 kW LP, 10 kW LP Test 68 Check Fuel Solenoid, Test 69 Check Choke Solenoid

Section 4.4

Diagnostic tests

Part 4

DC control

i.Set a VOM to measure resistance.

j.Connect one meter test lead to Wire 14 that was disconnected in Step 3.

k.Connect the other meter test lead to Wire 14 at J2-3. See Figures on Pages 92-95.

l.CONTINUITY should be measured. If CONTINUITY is measured, repeat Step 5 and then retest.

m.If CONTINUITY is not measured, repair or replace Wire 14 between the J2 Connector and the fuel solenoid.

Procedure: 8 kw Units

1.Set AUTO-OFF-MANUAL switch to OFF.

2.Set a VOM to measure DC voltage.

3.Disconnect Wire 14 from the fuel solenoid.

4.Connect the positive test lead to disconnected Wire 14 and the negative test lead to a clean frame ground.

5.Set the AUTO-OFF-MANUAL switch to the MANUAL position.

6.Battery voltage should be measured. If battery voltage is measured, refer back to flow chart.

Note: Disconnect the 7.5 amp fuse before discon- necting the J2 connector.

7.Disconnect the J2 connector from printed circuit board.

8.Set VOM to measure resistance.

9.Connect the positive test lead to disconnected Wire 14 and the negative test lead to J2 Pin 3.

10.CONTINUITY should be measured. If CONTINUITY is not measured, repair or replace Wire 14 between J2 Pin 3 and the fuel solenoid.

Results:

Refer to flow chart.

Test 68 – Check Fuel Solenoid

DISCUSSION:

In Test 67, if battery voltage was delivered to Wire 14, the fuel solenoid should have energized open. This test will verify whether or not the fuel solenoid is operating.

Fuel Solenoid FS1 Nominal Resistance – 27-33 ohms. Fuel Solenoid FS2 Nominal Resistance – 29 ohms.

Procedure: 8 and 12-20 kw Units

1.Install a manometer to Port 2 on the fuel regulator. See Figure 18 or Figure 20.

2.Set the AUTO-OFF-MANUAL Switch to MANUAL.

3.Proper gas pressure should be measured during cranking.

If gas pressure is measured, the fuel solenoid is operat- ing. If gas pressure is not measured, repair or replace the fuel solenoid.

Procedure: 10 kw Units

1.Remove the hose from fuel solenoid (FS2) and install a manometer to Port 2 on the fuel regulator. See Figure 19.

2.Set the AUTO-OFF-MANUAL Switch to MANUAL.

3.Proper gas pressure should be measured during crank- ing. If gas pressure is measured, both fuel solenoids are operating. Discontinue testing.

4.If gas pressure was not measured in Step 3, remove fuel solenoid FS2 and install a manometer to the bottom port of the fuel regulator.

5.Set the AUTO-OFF-MANUAL Switch to MANUAL.

6.Proper gas pressure should be measured during crank- ing. If gas pressure is measured, fuel solenoid FS1 is operating. Replace fuel solenoid FS2. If gas pressure is not measured, repair or replace fuel solenoid FS1.

Results:

Refer to flow chart.

Test 69 – Check Choke Solenoid

DISCUSSION:

The automatic choke is active cyclically during crank- ing and energized ON during running. For low speed exercise the choke will be closed.

The 12-20 kW units utilize a plate that covers the throttle bores. The choke is closed if the solenoid is not energized.

The 10 kW unit utilizes a throttle plate located in the choke housing and the choke is open when the solenoid is de-energized.

The 8 kW unit has a choke solenoid that is closed during the entire crank cycle when the solenoid is energized and the engine is cranking.

PROCEDURE: 10-20 kW Units

1.Operational Check: Set the AUTO-OFF-MANUAL Switch to MANUAL. While cranking, the choke solenoid should pull the choke plate open cyclically. The dura- tion of the cycle will vary depending on it’s position in the crank cycle sequence. Refer to the Crank Cycle Sequence Table on the following page for crank cycle sequences and duration times. If the choke solenoid does not pull in, verify that the choke can be manually opened. There should be no binding or interference.

2.Disconnect the C3 Connector.

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