Test Description

2002 Chevrolet Tahoe 4.8 V, 4WDSECTION Test Description

The numbers below refer to step numbers in diagnostic procedure.

  1. 2

    This step verifies fuel pump is operating.
  2. 4

    This step tests for an internal fuel leak. If fuel pressure decreases during this test, then an internal loss of pressure is indicated.
  3. 7

    This step inspects fuel pressure regulator for a fuel leak from atmospheric vent. If fuel leaks from fuel pressure regulator while fuel pump is commanded ON, replace fuel pressure regulator.
  4. 8

    This step tests for a loss of fuel pressure between shut-off adapter on fuel feed pipe and fuel pump.
  5. 9

    This step tests for a leaking fuel injector or fuel pressure regulator. If fuel pressure remains constant during this test, fuel injectors are not leaking fuel.
  6. 12

    This step tests for a restricted fuel return pipe. If fuel pressure is within specified values, a restriction in fuel return pipe is indicated.
  7. 14

    This step determines if fuel pressure regulator, or fuel pump, is cause of low fuel pressure. If pressure rises above specified value, fuel pump is okay.
  8. 16

    This step verifies that a circuit condition is not cause of a fuel pressure concern. Inspect all fuel pump electrical circuits thoroughly.

RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.