when i drive my car for awhile( 2-3hrs not str8, but around city) i have to depress my gas lightlier because my gas cuts off but and i have to depress it for it to cut back on.When i let the car rest for like 2-3 hrs it works fine again and it starts the whole gas cutting off cycle starts again if i drive it for awhile, one time it gotten so bad that i cant even go pass 2000 rpm with pressing the gas normally and i have to depress it to the thinnest to make it back home. Is this a sign of bad fuel pump?