a couple of days a go i got a weird idle surge problem

the car was idling up to 3000 then dropping back down (in park)

didn't know what the hell happend thought it was an alternator problem which was cause of a previous idle problem

today i purchased an alternator hoping it would solve the problem no dice WTF

i drive over to my friends to try to figure out what was wrong

i'm about 2 blocks away from his house when i was sitting at a light all of a sudden my idle jumped to 5000 WTF it tried to pull the car forward i shift to neutral (its automatic) shut the car off start it back up its doing it again i jam on the brake put it in gear and attempted to coast at whatever it was doing all the way to my friends house i rolled a stop sign shut off the engine and coasted next to his house pop the hood and find just below the fuel rail a huge crack