the car idles a 900 then it drops to 500 the goes up to 1100 and over and over......sometimes it stays a 900, but if i go driving and stop at a light same thing happens...........it never happened be for, it ran nicely. why now? what can i do to fix?

 

clean and check the iac. should fix the problem

 

mines been doing this since i got it, but it needs new plugs, opti rotor/cap and a waterpump!! so its not going anywhere hasnt even been on the streets