well my car recently got tuned a month ago, it doesnt want to start it kills my battery when i keep trying then i push start it n it will go but it struggles to get started and when it does it lags a little when i press the gas pedal? after a minute or two of constantly pressing the gas it will quit lagging....

my tuner said i was running lean at high rpms
Could it be the fuel pump or injectors?

 

Eh! Your tuner said!! Your tuner has to make sure you're fuel supply/maps is the right one across the whole RPM band, that's what he's paid for in the 1st place.

The usual checks, is your fuel pump priming? Are you getting fuel supply through the fuel rail and injectors, is there spark ???

 

Yes, but a tuner cant tune a setup that lacks in the fuel department. He cant make injectors run 100% duty cycle nor can he up the fuel pressure if theres no way to do that.

So your tuner said you were running lean on high rpm and you've been beating on the car? Lack of compression would make it hard to start