Well I have 3 s4 na and this is the first time this has happend to me I just got this one and it was sitting in a garage for about 9 months now I have had a few flooding problems with another one but Im not sure what the problem is. I have replaced the mass airflow senser fuel pump and reg. checked all fuses and it is getting fuel to the rails but not out of the injectors. I think i might be a computer problem let me know what you think cause the only spare part i dont have is a computer. thank you

 

You say that fuel is getting to the rails. So we can assume the pump is woking.

I had a similar problem. I had replaced my fuel pump and the car ran for a while. Then it would not start. I disconected the fuel hose (the one that come from the fuel filter) at the rats nest and had no pressure. TRY THIS. If you have no pressure then: 1. the fuel pump is sucking air. The filter at the pump is clogged or 2. Your fuel filter is clogged.
If you have pressure check the regulator.

 

I have replaced all of that that is why I am thinking it is a computer problem and the car does have plenty of fuel pressure. any other things I might check. Thank you