ok so i have a 05 GT 5 speed. bought the car last month, and i am having a issue revving the car over 4K rpms... when ever the engine is under heavy load, fast accel, it craps out at like 4k.. i can rev all the way up to like 6K when in neutral.. i dont know what it could be, i sea foamed the car today hoping that would clean inside and fix the problem , but did not, i dont know if its a clogged cat, coil packs, or spark plugs, any ideas?

 

I'd start with plugs. Be sure to read up on how to do it without breaking them. Ford used a high thread design of plug in 3v heads until 08 and they are prone to getting glued into the head with carbon build up. The seafoam probably loosened it up pretty good.

 

where can i get a good set of plugs, what are some good names?

 

Could also be a failing fuel pump or dirty fuel filter. An engine starved for fuel will rev up all day long in nuetral, but put it under a load and its a different story. Same is true for faulty spark plugs as already suggested. I would change the fuel filter and see if it helps, its cheap and easy to do. I know people use the champion 1-piece spark plugs and i think brisk makes a 1-piece for the 3-valve . I still have the stock plugs in my 05 gt.

 

ok thanks for the reply man, i will try replacing plugs and fuel filter this weekend!

 

Also make sure your traction control isn't on, could be as simple as you're losing traction when your hit the gas that hard and it cuts power.

Ric