It will start when I pour fuel down the throttle body, and I'm getting fuel pressure in the fuel lines, I've replaced the fuel pump and it ran fine, then the distributor rotor button cracked and I replaced that and it ran fine for about a week and a half. Then it started stumbling and cut off and wouldn't start back. I've replaced the TPS and Idle control sensor and it still will not start unless I pour fuel down the throttle body. could it be the injector(s)?