I have a 98 Avenger 2.0 DOHC....Two problems with it the a/c belt keeps runnin off the side of the power steer pump and i think its the tensioner pulley bc i can move it with my hand...But i dont wanna spend $150 on a pulley if thats not the case...

Also the car only wants to start when it wants....I can run it one second turn it off and the next second it wont turn back on...I was told it maybe the camshaft sensor so i changed it....and it still did it after i changed it....now im told its either the crankshaft pulley or my alarm system....The car turns over fine it just acts like it isnt getting and fire....any info on either subject would be very helpful....and if anyone has a cheap tensioner pulley that would probably be helpful to...thanks

Forgot to add that i already had it tested and nothing came up......when i got the car the timing belt broke and banged up the pistons, so i bought a whole new engine bored .20 over and a kid i know did all the work and the car started up fine before i had the new engine put in and since he put the new engine in it...it started to start when it wanted....