Usually I take the car for a spin and come home and park it for the day. Recently I have been driving the car on weekends for whatever is going on. I've noticed that if I turn the car off after it is up to normal operating temperature (180*) and let it sit for a while.....I have to hold the gas pedal to the floor and crank the engine for about 4 seconds before it will fire up.....Then of course, when it fires the exhaust smells like gas until it burns off. Carb or timing? I have a 1000A battery, a CS130 alt, and a MSD6AL so I know I have plenty of spark. Carb is the Holley SA 770. Mechanical fuel pump. FWIW, sometimes I notice that when the car is cold and has sat for a few days/weeks, the fuel filter is empty but several people have said that is normal.