System Test

With ambient temperature above 55°F, increase engine speed from idle to 3000-3500 RPM and check that plate and valve shaft of EGR control valve move upward as speed is increased. Disconnect wire from EGR solenoid and connect solenoid directly to battery. Repeat above test. EGR valve should not move. With engine running at idle, push up by hand on bottom of EGR control valve diaphragm. Engine should begin to run rough.