Toyota Repair: 1991 Toyota Tercel rough idel on warm days, 1991 toyota tercel, toyota tercel

Question
My 1991 Toyota Tercel idels rough and sometimes stalls on hot days or when stuck in traffic. What could cause this?  

Answer
The most common causes for this problem is an air leak on the intake side, possibly an intake manifold leak, another cause is the exhaust gas recirculation (EGR) system, the egr valve may not fully close at idle,check for any disconnected vacuum hoses, check the air intake tube from the air filter to the throttle body for any cracks)I'm assuming it's an EFI engine)have the EGR system checked.