Navistar N9, Diagnostic Manual

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40 1 DIAGNOSTIC TROUBLESHOOTING PROCEDURES
8.0 - Fuel System Operational Checkout Procedure
Step 1 Perform preliminary operational checkout procedure. Decision
Did you Perform 1.0 Preliminary Vehicle Operational Checkout Procedure (page 23)?
Yes: Go to Step 2.
No: Go to 1.0 Preliminary
Vehicle Operational
Checkout Procedure (page
23).
Step 2 Determine if engine has a fuel delivery problem. Decision
Perform Fuel Delivery Pressure (FDP) Test (page 2273).
Is fuel pressure between 60 and 100 psi?
Yes: Go to Step 3.
No: Go to 8.1 Fuel Delivery
Pressure (page 120).
Step 3 Determine if engine has fuel in the engine oil. Decision
Look for engine oil over full ¾ “ or more and smells like fuel.
Is fuel in the engine oil?
Yes: Go to Fuel in Engine
Oil (page 124).
No: Review operator
complaint.