My 2002 Honda Civic lx shakes bad when I start the engine from the car being cool or from sitting for awhile. The car seems to chug a bit like it is starving for fuel. My car tends to bog down causing me to lose acceleration while driving every so often. Once I press the gas a few times then it catches back up to speed and runs okay. I recently put a can of seafoam in my gas tank as well as with premium gas to try to see if anything was clogged and clear it out. This doesn't seems to be working. Could I need the fuel pump or regulator replaced?