Sometime my car will run fine and it will get warmed up, I'll start driving and when I get down the road it starts to idle really high (3000-3500 rpms), so I stop and shut the car off and when I start it up again and it runs fine. This only happens sometimes. I already know my choke is messed up and doesn't close properly, but wouldn't that make the problem occur consistently? I have an old 600 cfm Holley that was just rebuilt and tuned to get maximum vacuum at idle. Does anyone know what could be wrong?