2oo1 150 with a 5.4 had a problem were truck was not starting so i gave it a shot of starting fluid and it started right up. this went on and off for a week or so. Now it will start but sputters and drops to a sever low idle and stays that way for about 10 secs then stalls out... was thinking fuel pump but when it runs it runs hard no issues any ideas.. thank

 

Do a fuel pressure test.
When was the last time you changed the filter?