What is it that when you turn the key to the on posistion kicks on? Sounds Hydraulic, and cycles for 1-2 seconds.

I noticed tonight that my truck is making a little high pitched hum from around the same area with the car running. I never noticed it before, and it is only audible from the side of the truck. The engine drowns out the sound in the front of the truck. I did just put all the ignition stuff on Hydrashocker recommended, but can't see a preformance coil/wire/cap/rotor and new plugs (NOT BOSCH....) having anything to dom with it. I drove the truck and it ran like a champ. This little hum though, Normal? More of my Paranoia?

 

It maybe the ABS module, it does make a thump type sound for 1-2 secs, this normal, its just a self test.

 

It sounds more like a fuel pump to me and it's fine.

 

Agree with Mean Green, fuel pump.

 

Definitely the fuel pump. When ever I start mine up, I put the key to the on position until all of the console trouble lights go off to pressurize the fuel system, then engage the starter. I do it like that so I don't get excessive running of the starter motor (not that it does, I just don't want to burn it out). Try that sometime, as you will notice it fire right up, and not lag then fire.