Service Procedure
A. Reset basic timing:1. Connect a suitable tachometer and timing light.
2. With the engine at normal operating temperature, adjust basic timing from 12~ BTDC to 8~ BTDC using the applicable 1982 Service Manual procedure.
B. Inspect the EGR system and perform a speed drop test:
1. With the engine off and air cleaner removed, inspect the EGR system for signs of tampering (hoses removed, misrouted or plugged, parts missing). If any tampering is found, inform the owner that the tampering must be corrected, reinstall the air cleaner and proceed to Section D. If there are no signs of tampering, proceed with the following steps.
2. Disconnect the O2 feedback system at the two pin diagnostic connector (black and green wires).
3. Disconnect and plug the ESA vacuum hose at the ESA module.
4. Disconnect and plug the vacuum hose from the EGR valve and connect a hand held vacuum pump to the valve.
Note: Do not apply vacuum at this time.
B. 5. Restart engine.
6. Open the throttle slightly and set the fast idle adjusting screw on Step 2 of the fast idle cam.
7. After the engine speed stabilizes (about one minute), check the speed. It should read below 2500 RPM. Reset the speed if it exceeds 2500 RPM.
8. Apply full vacuum to the EGR valve (10" Hg minimum).
9. If the engine speed drops by at least 200 RPM, the vehicle passes the speed drop test.
- Turn off engine.
- Disconnect the vacuum pump, tachometer and timing light.
- Unplug and reconnect tge EGR and ESA vacuum hoses.
- Reconnect the two pin diagnostic connector.
- Reinstall the air cleaner.
- Proceed to Section D.
10. If the engine speed does not drop by at least 200 RPM, check for EGR valve stem movement by applying and releasing vacuum to the valve. If there is no valve stem movement, replace the valve using proper Service Manual procedures and perform the EGR speed drop test again.
^ For a vehicle within the 5 year/50,000 mile Emissions Warranty, file a separate warranty claim for the EGR valve replacement only, using labor operation number 25-01-45-01 with a 0.6 hour time allowance.
Note: A separate diagnostic allowance does not apply in this case because diagnosis is included in the recall labor operation.
^ For a vehicle beyond the warranty limits, inform the customer that the EGR valve replacement must be at the owner's expense.
If the owner does not agree to the repair expense, reassemble the vehicle as required and proceed to Section D.
11. If the EGR valve stem has definite movement and there is still not a sufficient speed drop when vacuum is applied, the EGR system is plugged and has to be cleaned.
C. Clean the EGR system:
1. Remove the carburetor, insulator, and isolator following Service Manual procedures.
FIGURE 1:
2. Clean the antechamber of the intake manifold, where carbon deposits have sealed the EGR passage, using a screwdriver or other sharp implement (Figure 1).
FIGURE 2:
C. 3. After as much carbon is scraped out as possible, insert a 12" piece of speedometer cable core into a drill motor. (Use a scrap piece or -- if necessary -- part of a stock cable.)
4. Using the speedometer cable core as a drill, alternate between using it and carburetor cleaner to remove additional deposits found in the lower part of the passage in the intake manifold and the EGR tube (Figure 2).
C. 5. After the passage is clear, vacuum it carefully to remove all scrapings.
6. Reinstall the carburetor, insulator and isolator.
7. Perform the EGR speed drop test again to assure that the EGR system is functioning properly.
8. After the vehicle passes the speed drop test:
- Turn off the engine.
- Disconnect the vacuum pump, tachometer, and timing light.
- Unplug and reconnect the EGR and ESA vacuum hoses.
- Reconnect the two pin diagnostic connector.
- Reinstall the air cleaner.
D. Install the Recall Completion Label:
1. With a ballpoint pen, print your dealer code (5 digits) on the supplied Recall Completion Label.
2. Peel the label from its backing and apply it to the radiator yoke next to the Vehicle Emissions Control Information Label.