2005 Pontiac Sunfire?

[zs138]

My sunfire has recently started revving up much higher then usual when I start it, about 3500 rpms, it use to be about 1500. It also sometimes takes several times to try and start it, why would this be. I need it for my job and want to fix it if it's a serious problem before it gets to bad.

 

[Jim R]

it may be your 02 censor you acn go down to your local autozone or a shop have them do acode check that will tell it all

 

[Don E]

Could be a defective battery due to a parasitic drain of low amperage to ground,defective alternator,bad cell in battery.The reason it revs up is the battery is low when you first start it and when it charges enough to run the computor the engine slows down.I recomment getting the battery load tested to see if you need to replace it.Could also be defective vacuum line leak.Check for leaking hoses and replace.