My 2000 S70 (205k miles) will turn over, but once I release the key it stalls. This has happened on occasion before, but I always managed to get it started after a couple of attempts. I have not noticed any correlation with the weather. When it does start, no warning lights come on. I haven't coded it yet, currently just sitting at work thinking about it. Any ideas?

 

Without more diagnostic info any suggestion as to what it could be would be strictly a guess.

That being said, I would ck the fuel pump relay first; a common issue on these cars.

 

It stalls when you release the key right after starting it? Can you get it in gear or anything?

Have you tried starting it in neutral?

 

+1 With GDog. Cranking but not starting is likely fuel pressure related. If you find that you have good fuel pressure, check for spark.