Silverado hard to start when warm

[Blue97]

MY 97 silvy starts good in the morning before work and fine after work , but if I stop on the way home for beer or what have ya and try to start it. It acts like the timing is off, but fires up and runs strong..

Been doing this for about six months now, I figured if its the battery or starter they would have died by now and it would of fixed itself lol.

I guess I will go have the battery tested and if good I will replace the starter just because..


Anything else I could look for while doing this.

Thanks


Edit........Just wanted to add , I lied up above....Last few days it is getting more noticeable in the morning aswell now.... starter engages , stops then spins... when warm the starter engages and stops then I turn the key again and it engages and slowly turns the engine but fires quickly . But while turning it acts as though its off time....