EGR System - Revised Testing Procedure: Overview
Number: 11-6-82Date: 01-13-82
Applicability: 1974 to 1976 - California Model
Only 1977 and on - All Models
Subject: Testing Procedures for Operation of EGR Valve
If you are inspecting the EGR system of one of the above listed models (see Applicability), use the following procedure for determining proper operation.
1. General Test of EGR System Operation
A. Allow engine to reach normal operating temperature.
B. While observing the EGR Pintle Valve (see Figure 1) through the side opening of the EGR Valve Body be sure that the Pintle Valve Shaft moves toward the EGR Valve Diaphragm as engine speed is increased to 3000 rpm - 3500 rpm. This test must be performed with the engine in a no-load condition.
C. If the EGR Valve Pintle Shaft does not move during the performance of Step B, disconnect the vacuum hose from the EGR Valve Inlet Pipe, plug the vacuum hose, and then connect a hand vacuum pump to the EGR Valve Inlet Pipe as illustrated in Figure 2.
D. With the engine idling, apply a vacuum of 7.9 in. Hg. (-2OOmmHg) to the EGR Valve with the hand vacuum pump.
E. If the idle speed drops by more than 300 rpm (or the engine stalls) the EGR Valve is operating properly; and the EGR vacuum source line is plugged. Check the source line in its' entirety using the applicable Subaru Service Manual to correct the problem.
F. If the EGR Valve Pintle Shaft does not move, or the shaft moves but the idle speed does not drop, remove the EGR valve and check the intake manifold/EGR port for blockage. If no blockage is present, replace the EGR Valve and again perform Step A to ensure proper operation.