starting issues

What is your question?

I have a 1990 Dodge Dynasty with a 3.3 v-6 engine. I have been experiencing intermittent no start issues. Symptoms are car will start and run rough from between 3-30 seconds and then die again. I have replaced the fuel pump and fuel filter. I appear to have good spark and good fuel pressure. I have never had a check engine light on this car. And to make it more interesting the car runs well when it does start. Lots of power without any hesitation. Thank you for your time