ENGINE STALLS FREQUENTLY OR DOES NOT DEVELOP FULL POWER (cont)

TM 10-3930-638-24&P

12-9. ENGINE TROUBLESHOOTING (cont)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

5. ENGINE STALLS FREQUENTLY OR DOES NOT DEVELOP FULL POWER (cont)

With engine operating at idle speed, squirt small amount of fuel on intake manifold where it contacts

Step 2.

cylinder head.

Check if oil is drawn into intake manifold indicating intake manifold gasket is damaged.

a. If oil is drawn into intake manifold, remove and replace intake manifold gasket (para 2-14d).

b. If oil is not drawn into intake manifold, proceed to step 3 below.

Step 3. Check engine oil level dipstick for over filled engine crankcase.

a. If engine crankcase is overfilled as indicated by dipstick, drain excess oil until level is just below

FULL mark on dipstick (para 2-14b).

b. If engine oil level is okay, proceed to step 4 below.

Step 4. Check for air in fuel system.

a. Place ignition switch in ON position.

Open bleed valve plug on top of secondary fuel filter

allowing air to bleed out of both filters.

When fuel. free of bubbles, starts to flow, close bleed

valve plug and wipe parts free of fuel.

Turn ignition switch off.

b. If no air in fuel system, proceed to step 5 below.

Step 5. Check for incorrect or contaminated fuel in fuel tank (if contaminated, fuel will have a milky white

coloring).

a. If fuel is contaminated, drain fuel tank, clean and fill with correct fuel (para 2-15d(1)) and replace

fuel filters (para 2-15e and 2-15f).

(Refer to current lubrication order for correct fuel.)

b. If fuel is not contaminated, proceed to step 6 below.

Step 6. Check for clogged fuel filters by disconnecting fuel line between fuel filter head and fuel injection pump

at fuel injection pump.

Place ignition switch in ON position and crank engine.

Fuel should be pumped out of disconnected line.

a. If fuel is not pumped out of disconnected line, reconnect fuel line and service fuel filters (para

2-15e and 2-15 f).

b. If fuel is pumped out of disconnected line, reconnect fuel line and proceed to step 7 below.

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