Conversion of Low Altitude System to High Altitude

Dealers in high altitude areas should encourage owners who have moved to high altitude counties to purchase the following adjustment procedure. This adjustment is considered an owner maintenance expense.

FIGURE 1:

1. Replace the EGR valve vacuum control assembly and vacuum modulator valve with the assemblies shown in Figure 1. Refer to Parts Information for part numbers.
2. Install magnetic tachometer probe and start engine. Allow

FIGURE 2:

engine to run until it reaches operating temperature. Set idle speed to specification then turn engine off.

3. Remove air crossover assembly. Install screen covers J-29657.

4. With transmission in park and A/C off, start engine.

5. Loosen locknut (Figure 2) and slowly turn metering valve stop screw clockwise until idle speed drops approximately 10 rpm.

6. Turn metering valve stop screw counterclockwise three
(3) turns. Tighten locknut.

7. Check for fuel leaks around metering valve stop screw.
8. Turn engine off.

9. Remove magnetic tachometer probe and screened covers from intake manifold and reinstall parts removed.

FIGURE 3:

10. Fill in dealer code and date on the supplemental emission control label, P/N 14057201 or equivalent (Figure 3). This label must be placed next to the existing underhood emission control information label. Wash off the area with soap and water, dry thoroughly, and apply the new label.

PARTS INFORMATION


Part P/N


1. EGR Valve Vacuum Control Assembly High Altitude
Application 22515542 or equivalent

2. Vacuum Modulator Valve 22516009 or equivalent

3. Label 14057201 or equivalent


SUGGESTED TIME

The suggested time to perform the High Altitude Adjustment and part replacement is 0.4 hour labor.