Econoline E450 V8-5.4L SOHC VIN L (1998)
Intake Manifold: Testing and Inspection
Intake Manifold Vacuum Test
Bring the engine to normal operating temperature. Connect the Vacuum/Pressure Tester to the intake manifold. Run the engine at the specified idle
speed.
The vacuum gauge should read between 51-74 kPa (15-22 in-Hg) depending upon the engine condition and the altitude at which the test is performed.
Subtract 4.0193 kPa (1 in-Hg) from the specified reading for every 304.5 m (1,000 feet) of elevation above sea level.
The reading should be steady. If necessary, adjust the gauge damper control (where used) if the needle is fluttering rapidly. Adjust the damper until the
needle moves easily without excessive flutter.
