I have a Nissan Maxima 2000 , car will start then dies . I changed the fuel pump and clean the iavc. And still have the same problem

 

Any codes? If cleaning the IACV didn't help, you probably need to replace it.

 

Do a bit of homework and search for "starts then dies" .... you may be surprised, but there are already 34 threads on this subject!
My bet is that you have to replace your IACV, but why don't you do a bit of reading and then we can compare notes.