Engine Test and Adjustments

Note. Do not add more than three shims,

When oil pressure still does not fall within limits

specified, replace faulty valve.

b . F u e l P r e s s u r e . Install a pressure gage in

place of the pipe plug (fig. 8-1) in the top, center

of the secondary fuel filter and / or water

separator to check fuel pressure. Fuel pressure

should be adjusted to 40 psi by turning adjusting

screw of the fuel pump (fig. 8-1). Turn screw

clockwise t o i n c r e a s e p r e s s u r e a n d c o u n -

terclockwise to decrease pressure. Refer to TM

9-2910-213-34 for further information on the

fuel pump.

c . Idle Speed. A d j u s t f o r s m o o t h i d l e a t 6 7 5

t o 725 rpm by turning idle adjusting screw (D,

Figure 8-3. Mean performance curve.

f i g . 4-85). Turn screw clockwise to increase idle

speed and counterclockwise to decrease idle

f. Acceptance Test. Repair all fuel and oil

speed.

leaks at start of test. Check again before engine is

d. Throttle Control Linkage. N o r m a l p i n

r e m o v e d from stand. At completion of test run,

travel on the vehicle control lever is ap-

check acceleration, idle, idle oil pressure, and

proximately 3 / 16 inch from the stop at both the

operation of governor. Acceleration should be

idle position and the full throttle position. W hen

c h e c k e d with

a m o d e r a t e steady

throttle

t h e pin travel is more or less than 3 / 16 inch

movement. If engine power is outside limits,

without spring movement, adjust rod to bring

check for cause and make correction. Gross

w i t h i n limits specified (fig. 4-85).

corrected horsepower shall be maintained

Manifold Heater. Pump fuel into the

b e t w e e n 735 and 765 horsepower. The governor

engine using a purge pump and press heater

shall be adjusted to limit the engine speeds as

button. If heater is operative, heat will be felt at

follows:

intake manifold turbosupercharger tube (feel

(1) Low idle - 675 to 725 rpm.

intake manifold turbosupercharger tube with

( 2 ) H i g h idle

(no

load)

2640

rpm

h a n d ) . When no heat is felt, check harness and

maximum.

h e a t e r spark plug for faulty connections. Inspect

Overhaul/ MWO Engine Data Plate.

purge pump and heater nozzle for proper

overhauled,

After

engine

install

operation. Repair faulty connections or replace

overhaul/ MWO data plate o n engine as

purge pump or heater nozzles.

outlined in TB ORD-1030.

f. Oil Consumption Check.

h . E n g i n e S t o r a g e . After engine has suc-

( 1 ) Inspect engine for oil leaks.

cessfully completed the acceptance test the

(2) Operate engine until normal operating

e n g i n e is to be stored or shipped in accordance

temperature is reached (180F).

with instructions provided in section II of this

(3) Idle engine for five minutes to allow oil

Chapter.

level to stabilize. Check oil level with engine

8-5.

Engine Test and Adjustments

i d l i n g , When necessary, add oil to bring level in

a. Oil Pressure.

Oil pressures shall be

o i l pan to full level, as indicated on level gage.

m e a s u r e d in accordance with paragraph 8-1i, (1)

(Refer to applicable Lubrication Order.)

a n d (2). The oil pressure regulator valve (D, fig.

(4) Operate engine for 1-1 / 2 hours at 2400

6-104) is adjustable, within limits, by the ad-

rpm and maximum horsepower.

dition or removal of washer-type shims (A)

(5) Idle engine for five minutes to allow oil

between relief valve cover and spring. Add shims

level to stabilize.

t o increase pressure and remove shims to reduce

(6) Check oil level, with engine idling, using

pressure. When oil pressure cannot be adjusted

oil level gage.

to within the 40-70 psi range, in this manner.

replace valve spring (C).

8-6