Startup issue

Can anyone explain why its been taking longer and longer for my truck to start? I noticed a few months back that it seemed to turn over a little longer than usual before staring.Now tho it almost never starts the first time the key is turned. It did light right up the second time i bumped it, but now it sometimes takes 3 or even 4 turns of the key.I have replaced the fuel pump, but naturally not with a factory unit, which i now understand to be the only real way to do it.Is the problem maybe a result of a weak pump?i cant seem to understand it,and i like to flatter myself a pretty good mechanic.i also replaced the pressure regulator and filter.

Did you do a fuel preasure test?
Have you looked at your plugs and wires lately?
It could be the starter coils too.

It does sound like a bad fuel pump or fpr. Do a fuel pressure test to confirm.