I have a 2010 GMC Sierra 1500 with 135k miles and when I put the pedal to the floor it takes at least 3 secs for it to rev up and get going. It has the power to go but it seems like it takes a second or to for it to realize that I'm flooring it

ive tried fuel injector cleaner it didn't help

any suggestions on what it could be would be much appreciated

 

You didn't say what engine you have but my son had the exact same problem with his 2009 Chev. with the 5.3 engine and the Auto Fuel Management (AFM) system. Along with the hesitation, he had numerous failures on the individual coils, error codes and the engine had excessive oil consumption. He took it to a dealer who said all the problems were caused by the AFM system (out of warranty at 84K miles) but they could fix it for $4500. No thanks. He purchased a device that would disable the AFM and keep the truck in V8 mode. He went to another dealer who said the cylinders that are shut down when in V4 mode would have a build-up of carbon and they also caused the oil burning. They had a procedure that cleaned the engine and de carbonized the cylinders. After this was done the truck runs like new. Now if the if the AFM disabling device can keep the engine clean... Good luck with it.