Installation manual

4-9

90-898305

Test Procedure

PUMP CAPABILITY TEST

Before proceeding with the system vacuum test, confirm that the pulse fuel

pump is capable of supplying the required vacuum. To do this, start the engine

and run at idle speed, pinch off/restrict the fuel supply hose between the

vacuum gauge and fuel tank, using tubing clamp.

Normal Reading 2.5 in. of vacuum (mercury) or higher,

proceed to fuel system leak test.

Reading below 2.5 in. vacuum

(mercury)

• Pump check valves defective,

replace valves

• Pump diaphragm defective,

replace diaphragms

• Air leak in pump, rebuild pump

with new gasket,

• check fitting for leaks

• Low crankcase pressure, check

for crankcase

• leaks or plugged pulse pump

pressure/vacuum

• passageways.

FUEL SYSTEM LEAK TEST

This test is done with the engine running, and the tubing clamp removed. The

clear hose that was installed previously is used to view the fuel flow to the

pulse pump.

No air bubbles seen in clear hose No air leaks, perform vacuum test

(following)

Air bubbles seen in clear hose Air leak on intake side of fuel system

• Pick up tube in fuel tank leaking

• Outlet fitting at fuel tank leaking

• Fuel inlet hose not properly

clamped at fitting

• Leaking fuel tank valve

• Fuel line from kicker engine

connected into fuel line of main

engine.

Notes

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