My 1999 5.4L won't start. It was initally an intermittent problem where the engine would crank but not start. Last time it wouldn't start for a week and I had it towed and it was fixed with a new fuel pump. This worked for 2 weeks but now it won't start again. My mechanic actually came to my house to look at it he said he wasn't getting any injector pulse. He replaced the relay, but no change. He's thinking some sort of electrical problem or a bad computer.

Has anyone had anything similar. Any ideas. Thanks.