My 03 Tahoe never starts on 1st try. It always starts on 2nd try. I replaced fuel filter, and fuel filter relay fuse. Strange when I took the fuel filter fuse out it started right away. Then started doing the same thing not starting on the 1st try. One guy said by taking the fuel filter fuse out I took off the over pressure of the fuel pump??? He said it is a too much fuel problem not a fuel starving fuel problem...

 

Have you checked the fuel pressure?

 

For sure check the fuel pressure should be steady at 55 to 65psi running and should hold for a while once the engine is turned off...
A way to check to see if you are getting too much fuel is to pull your dip stick and smell it, if it smells gassy they you may indeed have leaky injectors...

I suspect thou that you have a weakening fuel pump or bad fuel pressure regulator....