'94 Aero 5-speed with 234k.

When starting the 9000 while cold it will idle fine for about 30 seconds. After 30 seconds it will start to idle rough then die. It will repeat the process after restarting a few times until it heats up a bit then it won't start at all until it has sat for a while. It's not the fuel pump or the DIC because those were just replaced. I noticed that the APC was making a buzzing sound while the ignition was on. Any ideas of what's going on? Thanks.

 

usual causes are blocked,clogged/dirty air cleaner /or sensor.
vacuum leak at throttle body ,inlet manifold or hoses
spark plugs faulty
fuel injection fault.


some times i have found putting a bit of lubricant in the fuel, helps prevent the ,fuel pressure relief valve from sticking and causing problems ,
a few mls of two stroke oil in the gasoline works for me,

 

having said that ,i noticed that fuel quality makes a hell of a difference ,try using a higher octane fuel premium ,also the
ECu self checks and resets during start up ,checking temperature, fuel etc

have a look here at the Saab Central web site

2007 saab cold start rough idle

could be your answer is there