Just gkt done this swap and the 6.0 feels verry sluggish, i used the 6.0 l throttle body and crank sensors, and 5.3l injectors, its feels horrible any suggestions thanks

 

6.0 injectors and a tune.... What 6.0 did you go with??

 

Went with an 08 ly6 its not tuned yet wanna put miles on being a used engine to make sure its ok would seem to run better than this my turner said to use 5.3 injectors cause of the 5.3 tune could it be throttle body

 

Throttle bodies are same between 6.0 and 5.3 so i doubt it.... Is the 6.0 vvt??? Did you connect the vvt or delete it?? And does the 6.0 have dod?? If not is the dod deleted in the pcm??

 

Of course it feels sluggish. It needs a tune. The computer still thinks its feeding 5.3L displacement. All the fueling and timing parameters are based on the 5.3L.

Unless you have a flex fuel vehicle, the 5.3 to 6.0 injectors probally aren't a different rating.

 

The 5.3 injectors are smaller, usually around 30lb at 58 psi the 6.0 are usually all closer to 40lb/hr.... But fully agree tune could be the major issue unless hes trying to run vvt on a dod tune then theres all sorts of factors going wrong there

 

It is flex fuel the vvt isbt hooked up yet wires are there and waiting to get ecm flashed the 6.0 is not dod

 

Yeah youre gonna need a tune the pcm is probably still trying to disable cylinders, once the vvt is connected it, and everything is tuned it should feel a whole helluva lot better.... The 07up arebt as forgiving as the 99-06 were as far as tunes and swapping engines.... They dont relearn the way the older pcms did

 

Ok got the pcm back wired the two wires to the pcm pin 52 and 16. Still runs the same very lazy and no power. Did a back pressure test to rule out clogged cats everything is good. Did a key on engine off test for vvt magnet and you can hear it. did on engine run test and did a vvt actuator test and engine rose to 2000 rpm and sounded great. engine vacuum went from 14 t 20 inches. now if I put power to the front magnent and energize it engine vacuum dropps and motor runs rough. any suggestions or am I missing a wire. any suggestions thanks

 

At idle if youre activating the cam actuator its going to drop vacuum and run rough... Youre advancing the timing!!! Who is tuning it??