ARE THE CIRCUITS OK?
YES YES
26 CONNECT CONNECTOR D1245 TO THE ELECTRONIC SPEED SWITCH, S634.
DO THE APU DRY MOTORING (AMM 49-11-00/201).
DURING THE APU DRY MOTOR-ING, DO A CHECK OF THE OIL PRESSURE.
DID THE OIL PRESSURE INCREASE TO 4.0 PSIG (27.6 kPa)?
Starter Motor Turns the APU Engine but There Is No Combustion (No Increase in EGT)
Figure 113 (Sheet 4)
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ú 02 Page 156
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FROM SHEET 1
(BLOCK 1)
YES
NO
10 DO THE FLOW CHECK OF THE
FUEL SUPPLY SYSTEM TO THE APU
(AMM 49-31-00/501).
IS THE FUEL FLOW SUFFICIENT?
YES YES NO
11 DO THE APU DRY MOTORING
27 DO THE TEST FOR THE 67 ADJUST THE OPENING (AMM 49-11-00/201).OPENING PRESSURE OF THE PRESSURE FOR THE ACCELERATION
DID A CONTINUOUS FLOW OF ACCELERATION LIMITER VALVELIMITER VALVE (AMM 49-11-00/ FUEL COME FROM THE FUEL LINE (AMM 49-11-00/501). 501).FOR THE FUEL ATOMIZER? IS THE OPENING PRESSURE IF THE OPENING PRESSURE
OK? CANNOT BE ADJUSTED OR THE
NO
PROBLEM CONTINUES, REPLACE THE
YES
FUEL CONTROL UNIT (AMM 49-31-11/401).
NO
28 REPLACE THE FUEL CONTROL UNIT (AMM 49-31-11/401). START THE APU (AMM 49-11-00/201). DOES THE PROBLEM CONTINUE?
YES
YES YES29 DO A CHECK OF THE FUEL LINE BETWEEN THE FUEL CONTROL UNIT AND THE FUEL ATOMIZER ON
NO
THE COMBUSTOR UNIT.
IS THERE ANY DAMAGE?
SEE SHEET 7
NO
(BLOCK 34)
NO
30 REPLACE THE LOW-PRESSURE FUEL FILTER (AMM 49-31-21/401) AND CLEAN THE HIGH-PRESSURE
FUEL FILTER (AMM 49-31-81/ 301). DOES THE PROBLEM CONTINUE?
YES
SEE SHEET 6 (BLOCK 31)
Starter Motor Turns the APU Engine but There Is No Combustion (No Increase in EGT)
Figure 113 (Sheet 5)
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ú Jul 12/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
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A / GTCP85-129 SERIES /
737-300/400/500/ ENGINES /MAINTENANCE MANUAL ////////////////////////
FROM SHEET 5 (BLOCK 30)
REPAIR THE CIRCUIT FROM
FROM THE FUEL SOLENOID VALVE. THE FUEL SOLENOID VALVE, MOVE THE APU MASTER SWITCH CONNECTOR D1264, PIN B, TO THE TO THE "START" POSITION. SEQUENCING SWITCH FOR THE OIL
AFTER THE AIR INLET DOOR PRESSURE, CONNECTOR D1250, OPENS, DO A CHECK FOR VOLTAGE PIN 4 (WDM 49-31-01). AT THE FUEL SOLENOID VALVE, CONNECTOR D1264, PIN B (WDM 49-31-01).
IS THERE MORE THAN 11V DC AT PIN B?
YES
NO
32 MEASURE THE RESISTANCE AT
THE FUEL SOLENOID VALVE, CON-
NECTOR D1264, FROM PINS A TO B
(WDM 49-31-01).
IS THE RESISTANCE
20-45 OHMS?
YES
33 EXAMINE THE CIRCUIT FROM THE FUEL SOLENOID VALVE,
CONNECTOR D1264, PIN A, TO
GROUND (WDM 49-31-01).
IS THE CIRCUIT OK?
YES
REPLACE THE FUEL CONTROL UNIT (AMM 49-31-11/401).
Starter Motor Turns the APU Engine but There Is No Combustion (No Increase in EGT) Figure 113 (Sheet 6)
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PART NUMBER 305593 ú ú 02 Page 158 ú Jul 12/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
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FROM SHEET 5 (BLOCK 12) NO
YES34_______
WARNING DO NOT OPERATE THE APU WITH
THE LOWER SHROUD REMOVED IF PERSONS ARE IN OR DIRECTLY BELOW THE APU COMPARTMENT. YOU MUST BE A MINIMUM OF 3 FEET AWAY FROM THE OUTER EDGE OF THE APU COMPARTMENT OPENING TO OPERATE THE APU WITH THE LOWER SHROUD REMOVED. AN APU TURBINE WHEEL SEPARA-TION DURING OPERATION CAN CAUSE INJURY TO PERSONS. 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：737-300 400 500 AMM 飞机维护手册 AIRBORNE AUXILIARY POWER 1(31)
