Rough Idle
1. EGR vacuum hoses improperly routed.
a. Check hose routing; correct as necessary.
2. EGR valve leaking.
a. Check EGR valve operation.
3. EGR valve gasket faulty or bolts loose.
a. Check that EGR valve bolts are tight.
b. If bolts are tight, remove EGR valve and inspect gasket.
4. Vacuum improperly applied to EGR valve at idle.
a. Check vacuum from carburetor EGR port with engine at normal operating temperature and curb idle speed.