JLG 400S Service And Maintenance Manual page 205

STEP
15 1. Turn the ignition OFF.
2. Close the manual shut-off valve on the LPG tank.
CAUTION: When disconnecting LPG fuel lines, liquid LPG may be present. Perform this step in a
well ventilated area.
3. Loosen the fuel inlet hose fitting at the inlet of the LPL.
Was fuel present when the fitting was loosened?
16 1. Turn OFF the ignition.
2. Connect the test light to chassis ground and probe pin A of the LPL connector.
3. Crank the engine. The test light should illuminate.
Does the test light illuminate?
17 1. Remove the LPG fuel filter / LPL.
2. Remove the filter from the LPL.
3. Empty the contents of the inlet side of the LPG fuel filter onto a clean surface.
4. Inspect the contents of the LPG fuel filter for an excessive amount of foreign material or
water. If necessary, locate and repair the source of contamination.
5. Verify the LPG fuel filter is not restricted or plugged.
Was a problem found?
18 The fuel supply system or hoses are plugged or restricted, locate and repair the problem.
Is the action complete?
19 Replace the fuel filter. Refer to Fuel Filter Replacement.
Is the action complete?
20 Repair the open in the lock-off ground circuit.
Is the action complete?
21 Repair the open in the lock-off power circuit.
Is the action complete?
22 Replace the low pressure regulator (LPR). Refer to Low Pressure Regulator Replacement.
Is the action complete?
23 Replace the lock-off. Refer to Lock-off Replacement.
Is the action complete?
24 Replace the mixer assembly. Refer to Fuel Mixer Replacement.
Is the action complete?
25 The fuel supply system is operating normally, if a failure of the control solenoids is suspected.
Refer to Fuel Control System Diagnosis.
1. Install the test plug in the LPR secondary chamber.
2. If you were sent to this routine by another diagnostic chart, return to the previous diagnostic
procedure.
Is the action complete?
26 1. Disconnect all test equipment
2. Install the primary and secondary test port plugs.
3. Start the engine.
4. Using SNOOP or equivalent, leak check the test port plugs.
Is the action complete?
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Table 3-13. GM LPG Fuel System Diagnosis
ACTION
SECTION 3 - CHASSIS & TURNTABLE
VALUE(S) YES
- - Go to Step 23
- - Go to Step 20
- - Go to Step 19
- - Go to Step 26
- - Go to Step 26
- - Go to Step 26
- - Go to Step 26
- - Go to Step 26
- - Go to Step 26
- - Go to Step 26
- - System OK
- - System OK
NO
Go to Step 17
Go to Step 21
Go to Step 18
- -
- -
- -
- -
- -
- -
- -
- -
- -
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