a lot of times my car will not start without pushing on the gas to keep it running, especially on a cold start

Replace air filter, clean throttle with throttle body cleaner, replace fuel filter and add fuel injector cleaner to gas tank.

Thanks for the reply! I just installed a brand new fuel filter, air filter, cleaned the throttle body and mass air flow sensor (even though the Mass Air Flow Sensor is new), added injector cleaner a few days ago. I went to the local parts store and loaned a fuel pressure tester. Turns out I should be between 52-59PSI with the car off and the ignition switch turned on. I am only getting 40PSI at best and the second the fuel pump stops (after the two or so seconds that the fuel pump engages when turning on the ignition on) the PSI drops down to about 29. It should be holding pressure. When I hooked up the gauge to my fuel rail(3.4L V6) there was no residual pressure at all. I have checked for leaks in fuel lines, connections, fittings, fuel pressure regulator is brand new and isn't leaking (no gas coming out of the top of it when I pull vacuum line off, no gas smell in vacuum line) Over the course of the following ten Minutes, I watched the fuel pressure on the gauge drop down to about 20PSI and am now trying to figure out WHY I'm losing pressure? Fuel Pump is one thing, but that shouldn't be causing me to lose fuel pressure so rapidly once the pump stops. I'm totally open to suggestions on this one. When I replaced my fuel filter about a week ago, I got a LOT of gunk out of it, thinking that the sock/strainer on the pump is pretty clogged up with sludge inside of the tank? Next step is to yank the tank, at least I just filled it with gas the other day so it will be nice and heavy, LOL!

Fuel pump