TM-9-2320-272-10

TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)

TECHNICAL MANUAL; OPERATOR'S MANUAL

SEPTEMBER 2004

CHANGE 2

TM-9-2320-272-10 - Page 355 of 481

TM 9-2320-272-10

3-6

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

Table 3-1. Troubleshooting (Contd).

Step 3. Check to see if throttle control solenoid is functioning properly

(M939A2 series vehicles only).

If solenoid is malfunctioning, tie up with a strap or rope and finish

mission. Report to unit maintenance as soon as possible.

3. ENGINE CRANKS BUT FAILS TO START AT OUTSIDE TEMPERATURES BELOW

+32°F (0°C).

NOTE

Refer to Cold Weather Starting (para. 2-13).

Step 1. Check to see if fuel gauge indicates empty.

If empty, fill fuel tank(s).

Step 2. Check to see if emergency engine stop control on instrument panel is

pulled out.

Notify unit maintenance to reset fuel cutoff valve (M939/A1 series

vehicles only).

Step 3. Check ether starting system.

Operate ether starting system.

4. ENGINE STARTS BUT MISFIRES, RUNS ROUGH, OR LACKS POWER.

Step 1. Check to see if emergency engine stop control on instrument panel is

pulled out.

Notify unit maintenance to reset fuel cutoff valve (M939/A1 series

vehicles only).

Step 2. Check for restricted air cleaner.

If restricted, clean air cleaner element (para. 3-8).

Step 3. Check fuel supply system for water and impurities.

Perform service operation (para. 3-8).

Step 4. Check for air in fuel system.

Prime fuel system (para. 3-8).