ok so here goes i have an aftermarket fuel regulator and a walboro 255lph pump now i leave the pump hooked up the car will not run i unhook the pump starts great my fuel pressure is way below specs whyy am i flooding out? again if i leave the pump unhooked it starts i hook the pump back up it runs as long as i hook it up while it was running if i hook it uip before it runs it floods someone please help what could be my problem?

 

I'm guessing here because I can hardly understand what you have written. It helps a lot if you compose your thoughts in actual sentences, with punctuation and everything.

If your fuel pressure is way below spec, then the car will be to LEAN to start. Adjust the regulator so that fuel pressure is closer to factory spec.

What kind of car? TII? NA? Other mods? What regulator?