I have a 2003 Saab 9-3 convertible that is having intermittent starting problems. It seems to happen when the car has been driven long distances and the weather is hot or when it is raining. It cranks fine but will not start. When it is hot, I open the hood and it starts after about 10 minutes. When it is wet is starts after being cranked for a white. My mechanic has replaced the ignition cassette and the spark plugs and it has not fixed the problem.
You should try spraying a small amount of starter fluid into the intake to see if that helps get the engine running. If it does then you have a fuel problem. If you still get no reaction then you need to check for an ignition problem.
It’s been my experience that bad spark plug wires are most commonly at fault when an engine has starting problems in the rain. I would replace them.
In my experience of having this exact problem, I was told by a Saab mechanic that there is an automatic sensor that will not allow the car to turn on if it finds the engine is getting too hot. The problem only occurred at around its 10th year when other parts were failing. I found if I parked the vehicle in the hot sun for too long or in a warm garage or heavy stop and go traffic, the car would not start. I would hear a fan run constantly. As soon as that fan turned off, maybe with the help of opening the hood and cooling it off, the car would start up immediately. We did not find a solution. New spark plugs and an ignition cassette did not help. However I started to have an issue with my Idle shift. Perhaps the idle shift was the problem causing the car to run too rough and force the auto fan on which would not let the car run. We didn’t try finding a solution at that point because I am not a Saab fanatic or mechanic and the parts were becoming more expensive than the car’s worth. I loved the Saab but she is now in a better place, hopefully being used as parts for all of you who may need them. Good luck.
You’ve replaced the parts that would likely be the failure points, the ignition cassette and plugs. There are no plug wires so that leaves… Crankshaft Position Sensor.
This is a pretty classic failure mode for this part and this problem. It is failing, but hasn’t quite failed yet. I would suggest you have your mechanic replace it. The part is the same as a Chevy Cobalt part, $20, and it is fairly easy to get to on the front, driver’s side of the engine so labor should’t be too expensive.