Pickup 2WD L4-155 2555cc 2.6L SOHC VIN E 2-bbl (1988)
Altitude Compensator: Testing and Inspection
California Vehicles
Testing at Elevations Below 1,200 M (3,900 FT.)
Fig. 160 Testing check valve
1.
Warm up the engine until coolant temperature is greater than 85 degrees C or 185 degrees F.
2.
Connect a timing light to the engine and remove the air cleaner.
3.
Disconnect the vacuum hose (black) from the carburetor primary emulsion well bleed nipple and plug the nipple, Fig. 160.
Fig. 161 Testing high altitude compensation system (below 3,900 ft.)
4.
Connect a hand vacuum pump to the vacuum hose and verify that vacuum is held while the engine idles, Fig. 161.
5.
Connect the disconnected vacuum hose to its original position.
6.
Run the engine at idle and verify that the ignition timing is set to 8 degrees BTDC for the 2.0 L engine and 7 degrees BTDC for the 2.6 L engine.
Fig. 153 Testing vacuum regulator valve system
