Fuel Pump? Relay? Inconsistent Starting

[thedome]

Hello,

I'm having and inconsistent issue starting my the cobra with a Rousch 427R. The car has just over 800 miles on it and recently I've had an issue where the car doesn't start consistently. It cranks and everything is fine in regards to the starter but it just does not fire up. I believe that have narrowed it down to something in the fuel system (pump?, relay? ). I have noticed on a cold start that I do not always hear the fuel pump "humming" for those first few seconds as it would normally pressurize. Mine does not have a separate fuel pump switch and it's wired to the ignition key. When I don't hear that humming I know it wont start and sure enough it doesn't. I have fuel injection/throttle body setup with an intank fuel pump. I have pulled the fuel pump relay and inspected. I am going to replace it for the heck of it but I don't think that is the root cause. I thought maybe the fuel pump was\is the issue but being so new I suspect that is not the issue. I inspected the top of the tank and confirmed the wiring to the fuel pump was not loose or anything. I even went as far as tapping the top of the tank\fuel pump lightly with a hammer to see if something was\is sticking. On a couple "weird" occasions I pulled the gas cap off and tried starting it and it actually worked? The last few times that trick has not worked so don't think its a vapor lock or related to that. Stumped....