grand am wont start

i have a 87 grand am 4 cyl that every once in awhile it wont start it will turn over fine but not fire, i put new tune up on it,and it started up but started acting up again, it is not flooded, i even tried putting gas down carb after sitting and same thing. but all of a sudden later it will start, it also is making a humming noise from under the hood could it be a fuel pump or what, open to any ideas, thank you

hey badgervine, well this sounds lik the coils may be going out. Reason being, later in the day after the engines warmed by the sun, the short in them makes contact untill they cool down. expantion and contraction.

as far as the humming sound I'm not sure what would be doing that under the hood. The fuel pumps in the rear tank. You should here that when you turn the key on. Heres a link to explain the gas tank and pics of the pump and float. You might find somthing usefull there.

http://www.autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/0e/58/cd/0900823d800e58cd.jsp

BTW- the link also has instructions on how the test the coils too. Good luck & Happy Holidays!