29 Roadster won't idle all the way down

[Jim M]

My roadster is running fine but when I come to a complete stop the engine does not idle all the way down. If I put my toe under the accelerator pedal and pull it back it then idles all the way down. I can not find any info in either of Les Andrews books about the linkage on the firewall. Before I start taking it apart would like to know if anyone else has had this problem and what cured it. Thanks, Jim