my 04 did this sence i got it, then i put new injectors in it it stopped until a few months ago it back at it again.

 

today, while stopped on the highway, at full operating temp, I noticed it happening. There is a loud CLICK, such as a relay kicking, then the hiccup. every time.

Now just have to figure out what is making the noise. I was thinking perhaps A/C clutch relay or some such thing, but I will look more closely later on.