2003 Chevy Cavalier 2.2L - RPMs Surge & Drop Out - Stalls In Idle

Hello,

My Chevy cavalier is having issues in idle. When we turn the car on, the RPMs go up and down...it revs up to 3000 RPM and then stabilizes at 1000 RPM. Sometimes it won't hold and will drop out.

When we drive, the car will sometimes shut off when in idle. It isn't just when we are stopping. Even at high speeds, the car will shut off if put into idle. Sometimes it will turn back on easily but other times it is a struggle.

We also noticed that if we put the AC on, the extra load will keep the car from dropping out.

We already replaced the fuel pump (it failed at 60,000 miles).

Any suggestions? Thank you.