My 2004 tucson refuses to start after I changed the fuel pump and filter. The engine cranks, and may start with very low revs for about three seconds and then cuts off. The fuel pressure is weak.

Thanks for any ideas on fixing this problem.

 

I had the same issue on mine. After fuel filter and fuel pump replacement, it turns out the fuel relay under the hood had bad contacts in the relay box. Yes, the bottom of my relay box is corroding and not making contact and only way to fix it is hard wiring the relay or replacing the entire box. I went with hard wiring the relay