wont keep running

[cosmo358]

Hi everyone Cosmo358 here. I joined the forum because I,m really stumped with a problem on my 2003 pulsar. I recently bought a 2003 nissan pulsar n16 auto sedan for my daughter as a birthday present with only 188207kms on it. she really loves it. For the first few days the car run great then had to replace battery as old one wouldn,t hold charge. now the car will crank, start then run for about 5 seconds. then stop  I,ve replaced all sensors including crank and camshaft sensor. had fuel pump and immobiliser checked out and are working fine. As I,m good with mechanics I keep coming back to a view that something is stopping the fuel pump from running only allowing it to prime then stop. have been told it maybe power train control module but I,m stumped as to where it is located on my car. if any members have had a issues like this I,d really appreciate any advice as to how you resolved it. I,m open to any advice cheers Cosmo

[Trevor]

Was there any possibility that the battery terminals were reversed or the positive lead connected last?