EGR Functional Tests

1. Start engine and operate at idle speed.
2. With coolant temperature below 131°F, increase engine speed to 2500 RPM and check to ensure that secondary EGR valve is not operating. If secondary EGR valve is operating, replace thermo valve.
3. Allow coolant temperature to exceed 133°F, then increase engine speed to 2500 RPM and check secondary EGR valve operation. If secondary EGR valve does not operate, check EGR control valve and thermal valve and replace as necessary.
4. Disconnect green stripe hose at carburetor and connect a vacuum pump to vacuum hose.
5. While operating sub-EGR valve by hand, apply 5.9 inches Hg of vacuum with vacuum pump.
6. If idle speed becomes unstable, the secondary EGR valve is operating properly. If idle speed remains unchanged, replace EGR valve.
SERVICE BULLETIN: On 1983 Challenger and Sapporo federal models with 2.6L engine and manual transmission, engine surge may be noticed during constant speed driving. To correct this condition, remove primary main air jet No. 95 (next to the choke blade housing) from carburetor using an expandable tip screwdriver and install replacement jet No. 65 (part No. MD606848). After installing new jet, locate sub-EGR valve adjusting screw and apply suitable solvent to soften sealant. Turn adjusting screw counterclockwise 3/4 turn, then apply suitable sealant to screw threads and paint screw head white for identification.