Car Won't Start

[renegade8999]

I just purchased a 89' 240 and the kid that owned it previously had done some "cute" wiring for his stereo. The ground had come undone on the sub though and i had a friend over that loves working on and tuning stereos so i told him have at it. He regrounded the sub and got whole system working great and i was completely happy... till i tried to start the car. the car cranks but will not start up at all. i have checked all the fuses and took the opportunity to replace all the spark plugs and wires but i still cannot get the damned thing to start... tried jumping it just for extra power but it cranks and cranks and nothing. Please any ideas are appreciated

also i tried unplugging the entire stereo after, ground and all. No change.