TM-9-2320-260-34-1
TRUCK, 5-TON, 6X6, M809 SERIES (DIESEL)
TECHNICAL MANUAL; DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE; VOLUME 1 OF 2
JULY 1994
TM-9-2320-260-34-1 - Page 26 of 657
TM 9-2320-260-34-1
Table
2-1.
Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
20.
21.
22.
NO FUEL AT FUEL INJECTORS
Step 1. Check fuel injection pump fuel shutoff valve for proper operation and adjustment. Place fuel
-
shutoff cable control in RUN position. Confirm valve on fuel pump is in proper position.
a. Replace fuel shutoff cable if fuel shutoff valve is not in proper position
(TM 9-2320-260-20).
b. Replace fuel shutoff valve if fuel shutoff valve is in proper position (para. 5-15).
Step 2. Check if electric fuel shutoff solenoid has power when ignition is on.
Replace electric fuel shutoff solenoid if still no fuel at injectors (para. 5-15).
NOTE
Air entering fuel delivery lines may block fuel flow. Air can enter
a line(s) when a fitting(s) is loose or a line(s) or a fitting(s) is
defective. This is indicated by leaking fuel.
Step 3. Check fuel injector nozzles for proper operation. Remove fuel injector nozzles and bench test
(paras. 5-6 through 5-11).
a. Clean, adjust, and retest fuel injectors if operation is incorrect (paras. 5-6 through 5-11).
b. Replace fuel injectors if fuel injector nozzles are defective (para. 5-6).
END OF TESTING!
LEAN FUEL FLOW AT INJECTORS - LOW POWER - LOSS OF POWER
Step 1.
Step 2.
Step 3.
Step 4.
Check for incorrect fuel injector and valve adjustments.
Adjust injectors and valves as necessary (paras. 3-82, 3-83, and 3-84).
Check fuel injectors for proper operation.
Clean or replace fuel injectors if defective (para. 5-6).
Check fuel pump for proper operation.
Replace fuel pump (para. 5-13) with known calibrated fuel pump.
a. Check fuel tank and fuel supply lines for restrictions if lean fuel flow condition is
confirmed (TM 9-2320-260-20).
b. Replace fuel pump if now there is full fuel flow to fuel injectors (para. 5-13).
Check cylinder heads and fuel crossovers for obstructions or leaks.
Clean fuel passages, correct leaks, or replace parts (paras. 3-17 and 3-18).
END OF TESTING!
EXCESSIVE EXHAUST SMOKE AT IDLE AND UNDER LOAD - EXCESSIVE FUEL CONSUMPTION
Step 1.
Step 2.
Step 3.
Check for incorrect fuel injector and valve adjustments.
Adjust fuel injectors and valves as necessary (para. 3-82, 3-83, or 3-84).
Check for dirty or damaged fuel injectors,
Remove, inspect, and clean dirty injectors. Replace fuel injectors if damaged (para. 5-6).
Check fuel pump calibration. Remove fuel pump (para. 5-13) and substitute known
calibrated fuel pump.
a. Replace fuel pump if excessive smoke condition is corrected (para. 5-13).
b. Perform step 4 if excessive smoke condition is not corrected.
2-12
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