idle problem!!

[Ramonesfreak2010]

Last Saturday I was driving home and when I got a red light, I realized my rpm was at 1600. Its usually at 900rpm during idle. So I shut off the car and tried to turn it back on. It wouldn't crank. After the third time of trying, it started up again and my idle was back at 900rpm. A couple hours later, it happened again and one last time at night. Since then, it does it constantly. Yesterday, I cleaned my throttle body and used fuel injector cleaner too see if it helped. It did for a couple hours but then came back.

All day today, its been idling at 1600rpm throughout most of the day. When I shut off the car, it doesn't start so I have to push start it. But, when the idle is at 900rpm, it starts normally. It does smell like gas in my car and when I accelerate, the engine jerks a little. Also, there is a lot of backfire.

Any help would be appreciated.

[240_SeX]

I'd do a boost/vacuum leak test to start.