This all started when I disconnected my battery and recharged it. My car drives perfectly normal but I know I need a new battery. Sometimes when I'm done driving I put it in park and the idle fluctuates in waves. The rpm literally goes up and down like when the vacm hose is off. But the other day I started my car it did this and turned off. I checked for vacum leaks already. What could be the cause?

 

how much does it go up or down. if it goes up to 2.5 k and then back down. try cleaning or replacing your iacv. if its only alittle adjust your idle with the screw on top of the tb

 

ok.....ill check that