car shakes when i push the pedal?

hello all i have a bit of a problem again first off i have a 94 grand am gt 3.1 v6 and i just dont get it? every time i am driving sometimes only sometimes when i give it some gas while the car is running on the highway or in town the car shakes so much then if i let go of the pedal and push it again it goes away and it will come back later or if not in a couple of days. anyone know what this could be??

If the check engine light isn't on two possibilities. Bad motor mount or a bad CV joint in one of the front drive axles. Since it only does it when you hit the gas I would discount the tires and brakes.

Could also be the fuel pump or injectors. Check your fuel filter also.