Did this work for you? Going through the exact same thing myself with an '02- just replaced the pump, ran great for about 4 days, now it hit or miss most mornings and never fails once it starts up. Relay is good, about to pull the PCM and have it checked out; but don't really want to do that if I don't have to.

 

Did not change the switch. I found a blown fuse for the power to read codes. Replaced the fuse, read codes and repaired what was wrong. It is much better now, but astill acts up on occasion.

 

Thanks.
I'll post something to this thread for the next guy when I get mine figured out.