COLD WEATHER STARTING (BELOW +32°F) (0C) (Contd)
If engine needs additional ether to prevent stalling, perform step b. again.
At temperatures below 0°F (-18°C), M939A2 series vehicles will need to be repeated up to six
times before engine will start. The engine start switch on the M939A2 series vehicles must be
held in the START position to inject ether.
Check your instruments again (para. 2-12).
If necessary, pull out hand throttle control (2) until tachometer (4) indicates an operating range of 700-800
rpm (800-1000 rpm on M939A2 vehicles).
Allow engine to warm up approximately ten minutes. If engaged, disengage hand throttle control (2) by
rotating handle and pushing in to allow engine speed to drop to idle after warmup period.
Stop engine immediately by pulling out EMERGENCY ENGINE STOP control (7) if at any time one or
more of the following conditions arise:
Noisy engine and/or excessive engine vibration.
Engine oil pressure does not register, or suddenly drops to less than 15 psi (103 kPa) on M939/A1
series vehicles or 10 psi (69 kPa) on M939A2 series vehicles, as indicated by engine oil pressure gauge (6).
Sudden increase in engine coolant temperature as indicated by engine coolant temperature gauge
(5). Normal operating temperature is 175°-200°F (79°-93°C).
Engine continues to run after ignition switch (1) and battery switch (3) are turned to OFF positions.
After an emergency shutdown, the engine will not restart until unit maintenance resets the fuel shutoff
valve. On M939A2 series vehicles, position EMERGENCY ENGINE STOP control (7) to reset.