TM-9-2815-220-24

AVDS-1790 2CA, 2DA and 2DR Air-Cooled 12-Cylinder Diesel Engines

TECHNICAL MANUAL; UNIT, DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE MANUAL FOR AVDS-1790 2CA, 2DA and 2DR Air-Cooled 12-Cylinder Diesel Engines

TM-9-2815-220-24 - Page 139 of 1563

TM 9-2815-220-24

ENGINE PERFORMANCE LOW

0019 00

THIS WORK PACKAGE COVERS:

WP 0019 00-1

Troubleshooting Table and Diagnostic Tests

INITIAL SETUP:

Tools:

General mechanic’s tool kit (item 121, WP 0176)

Personnel Required

Track Vehicle Repairer (2) 63H10

Equipment Conditions:

Engine installed in vehicle or ground hop.

CAUTION

If a rough, noisy, or overheated engine is associated with the reported

low power, prior correction of these malfunctions often will eliminate

the poor performance and, in addition, may prevent further damage

to the engine.

When low power or poor vehicle performance is reported, an engine

"stall" speed test will indicate whether the malfunction is engine or

vehicle related.

PRELIMINARY INVESTIGATION

PROBABLE CAUSE

CORRECTIVE ACTION

a.

Engine rough operation.

(1) Refer to WP 0014, Engine Rough

Operation.

b.

Engine noisy.

(1) Refer to WP 0015, Engine Noisy Operation.

c.

Engine overheating.

(1) Refer to WP 0017, Cooling System

Deficiencies.

POWER VERIFICATION: Perform engine "stall" test as follows:

PROCEDURE

OBSERVATION

ANALYSIS

Start engine and warm to normal operating temperature (140

°

F).

With vehicle brakes

applied and

transmission in "high

range," depress

accelerator pedal fully

and operate engine for

20 seconds, release

accelerator pedal and

allow engine to idle

1 minute.

Engine speed below 1800 rpm.

NOTE

Use a calibrated tachometer for

"Stall Test".

CAUTION

Limit "Stall Test" to 30-second

intervals maximum, and terminate

immediately if transmission warning

light activates.

Engine and

transmission partially

warmed up (not to

normal operating

temperature of 140ºF).