I read the instructions on loading my tunes and it says to remove the fuel pump fuse before beginning. It also says that the new 2004-2007 trucks usually don't have a separate fuse for the fuel pump. I have a 2007. There is a fuse that is labeled "Fuel pump relay, Fuel Injectors, Intake Manifold Runner Control (4.2L) all for the same 20 amp fuse and I was wondering if that was the same and is it still required to be pulled. I have pulled it just to be on the safe side. I emailed them and asked the same question but I am leaving for the weekend and thought I might get a quicker answer here sinse they are buisy. Thanks.

 

No - 04+, returnless fuel system - you don't have to.

Absolutley won't hurt if you do though.

 

Thanks MGDfan, that's what I was hoping to hear. I'll let you guys know how the towing tune works out when I get back.

 

I believe they instruct you to do that so you don't pressurize your fuel line by having the fuel pump turn over and pump fuel to the engine. My Superchips 1715 was that way with the instructions, I did have a separate fuse for the pump and pulled it every time I did any programming. I would take the safe route and pull the master fuse you are referring to that handles more than just the fuel pump itself. Of course, my superchips only wanted the ignition in the ON position, never advanced to the crank position.

 

I only turn the key to the ON position as well without starting it but I believe the reason for pulling the fuse is so that the pump doesn't energize and rob power from the tuner.

 

Hi.

Actually guys - the main reason is, during the flash process on the older PCMs' (and older fuel systems), it was found that sometimes the pump/injectors would inadvertantly pulse - filling the cylinders with fuel - worst case hydrolocking the engine.

So - CYA by Superchips/SCT.