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Couple of guesses. Your temp sensor may be defective and sending the ecu the wrong info in a certain temp range which would cause a rich or lean condition.
Another guess. The fuel return check valve may not be holding pressure. When you let it sit warm, the check valve allows just enough pressure to leak to make it difficult to start. There might be enough fuel pressure to allow it to start, but then it would quickly run out of pressure because the fuel pump wouldn't have caught up yet. Then your cranking rebuilds the pressure sufficiently to start/run. When starting immediately when hot, it hasn't lost enough pressure to cause problems. But that wouldn't explain why you can start cold...How is it when you try to restart right away when warm? You only mentioned warm start after sitting.
Another guess (ok, that's three...). Vacuum leak - that would explain your high idle.
Fourth...you cleaned the aic, but the aic is actually bad. I had an older 900 where the aic was only bad in a certain range of operation. I don't remember the specifics, but I think it was that it was prone to conditions like that (at least for those years) because they would operate in it median range most often. This constant operation in a small range would caused a "flat spot" in the valve operation. I believe Saab aic valves are "duty cycle" based. The pulsed signal determines how wide the valve opens. I'm not sure if Saab valves do it, but in Toyota valves, an electrical failure (internal or external) causes the valve to "float" at a point midway between extremes. This would cause an idle of about 1200 rpm (which is high, but not st*pidly high). That may explain you high idle issues along with some of your warm start issue.
Below is a link on how the different types of valves operate (it's for Toyotas, but you'll get the idea of what occurs).
posted by 98.229.227...
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