Alfa Romeo Repair: rough after warm, bosch fuel injection, vacuum leaks

Question
the car runs well until I turn it off, 5 mins later (still warm) if I restart it it runs real rough for about 10 min and then its fine again. The silicon hoses I was refering to are vacum hoses for the bosch fuel injection.e sThanks for yor response
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-----Question-----
I have a problem w/ my 1985 graduate that after it warms up and I turn it off, when I restart it runs extremely rough, I was going to purchase new silicon hoses for the fuel system thinking a air leak ?
-----Answer-----
If you mean the fuel line, those hoses are not made with silicon--they are high pressure hose that is black in color and specifically for fuel injection. But that is not the problem. I need more info to give you a lead. In the meantime check the tune and tell me how long the rough running persists and before shut off while driving is there any driving problem.

Answer
Most vacuum leaks are persistent, however, sometimes a crack can open intermittently. Check with hand pressure the intake hose from airflow sensor to throttle body. However, what I would first inspect in this situation is the cold start injector system. The thermo time switch may be malfunctioning or the injector could be leaking.