in the morning my car cranks 10 seconds before start then is fine until i let it set for a few hours. This started since i change fuel filter, but i see no leaks.

 

What year/model/engine?

 

88 t/a 350 tpi

 

f/p relay? Sounds like it's waiting to build oil pressure before the pump gets power.

 

If RedDevil isn't spot on you might want to check the voltage. Battery could be draining somehow then it stays charged for a couple hours after the alt gives it a small charge.

Does it crank slow or crank normal but just longer?

 

Cranks normal

 

Check the cold start injector or the cold start sensor? May be worth lookin at.

 

I've had this problem with an old TBI camaro I once had. I needed to press the gas pedal for it to take less than 10 seconds to start. Turns out I had leaky injectors and pressing the pedal put the vehicle in 'clear flood' mode which is something like 20:1 A/F ratio. If pressing the throttle pedal when cranking helps your situation then I would look at your injectors.