Ford Ranger Maintaince And Repair Manual page 532

Exploded view of the EGR system and related components for the 4.0L engine
System Integrity Inspection
Check the EGR system hoses and connections for looseness, pinching, leaks, splitting, blockage, etc. Ensure
that the EGR valve mounting bolts are not loose, or that the flange gasket is not damaged. If the system
appears to be in good shape, proceed to the EGR vacuum test, otherwise repair the damaged components.
EGR System Vacuum Test
The EVR solenoid has a constant internal leak; this is normal. There may be a small vacuum signal,
however, it should be less than 1.0 in. Hg (3.4 kPa) of vacuum.
Start the engine and allow it to run until normal operating temperature is reached. With the engine running at
idle, detach the vacuum supply hose from the EGR valve and install a vacuum gauge to the hose. The vacuum
reading should be less than 1.0 in. Hg (3.4 kPa) of vacuum. If the vacuum is greater than that specified, the
problem may lie with the EVR solenoid.
EVR Solenoid Test
1. Remove the EVR solenoid.
2. Attempt to lightly blow air into the EVR solenoid.
1. If air blows through the solenoid, replace the solenoid with a new one.
2. If air does not pass freely through the solenoid, continue with the test.
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HOW TO USE THIS BOOK
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COMPONENT TESTING