EXP L4-098 1.6L VIN 2 2-bbl (1983)
EGR Valve: Testing and Inspection
Without Back Pressure Transducer
Single Response Tests
1.
Check all system vacuum lines for proper routing and secure connections.
2.
Inspect vacuum lines for wear or damage and replace as necessary.
3.
Ensure there is no vacuum to valve at idle. Recheck hose routing if vacuum is present.
4.
Ensure that there is vacuum at valve at 3000 RPM on 4-140 engine, or kickdown RPM on other engines, with engine at operating temperature. If
there is no vacuum, trace system vacuum lines back from EGR valve and replace components as necessary. Refer to vehicle emission decal for
kickdown RPM specification.
Valve Function Test
1.
Run engine at idle and apply 8 inches Hg vacuum to valve. Valve stem should move, opening valve, and engine should roughen.
2.
If valve stem moves but engine does not roughen, remove valve and clean inlet and outlet ports with fine wire brush. Do not use sand blasting or
gasoline to clean EGR valve.
3.
Run engine at idle and trap and hold 4 inches Hg vacuum.
4.
If vacuum drops more than 1 inch Hg vacuum in 30 seconds, replace valve.
Seat Test
This test should be performed when the valve is suspected of leaking, indicated by rough engine operation.
1.
Install blocking gasket (no flow holes) between mounting and valve, then retighten valve.
2.
Improved engine operation indicates a defective valve. Clean or replace as necessary.
3.
Replace blocking gasket with conventional gasket.
