JonW Posted April 14, 2023 Share Posted April 14, 2023 (edited) When my 1960 Pontiac Catalina with 398 2 bbl cold starts, it fires up right away, but the longer it idles, the higher the high idle goes. It must go to 3000 RPM or more, and it won't kick off until the engine warms up. In the photo below, is the screw indicated with the arrow the high idle speed screw? Which screw is the regular idle adjustment screw? Edited April 14, 2023 by JonW (see edit history) Link to comment Share on other sites More sharing options...
Oldtech Posted April 14, 2023 Share Posted April 14, 2023 The screw you indicate is the only idle speed screw. As the choke comes off the flat link lets the cam down. It won't change until you tap the pedal which releases the cam. All this has to be perfectly free and the choke set properly. If it is speeding up with the screw on the low speed section as in the picture, you have a vacuum leak. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now