Bobcat 430 fasttrack

Hi all. I’m in need of some help with my 2004 model bobcat 430 fasttrack. The machine has worked without any problems for the last few years since owning it. Now all of a sudden the excavator will start up fine, run, dig, track all perfectly for approx 1hr. Then all of a sudden it will loose Revs under a bucket load of material and wants to stall out and die. You start it back up, the revs pick back up to where it should be normally, try to move the bucket load of material and struggles again and dies in the arse. If I leave the machine turned off for a while and let it cool down I’m able to operate the machine worry free for approx 10-15min until these problems arise again, and I have to repeat the process of turning it off cooling it down and repeat. Now I have changed the fuel lines from the tank to the fuel pump, new fuel filters, put brand new diesel in the tank, new thinking this will fix the problem. I am now thinking could it be something with the injectors? Do I need new ones? Is this an easy fix or is it something else. Would appreciate all the help with this to get it going again.