Rochester carb/ 74 Corvette
Le Mans Master
Joined: Mar 2008
Posts: 5,948
Likes: 72
From: Oxford MA-----You just lost the game!!!!
If the choke and fast idle are set correctly, a slight stab of the gas pedal should bring the high idle down after the engine runs for a few seconds, definitely less than a minute. Is this not happening?
Scott
Scott
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,391
From: At my Bar drinking and wrenching in Lafayette Colorado
Fast idle speed screw is on the passenger side of the carb, below the choke linkage. The screw head faces forward. Back the screw out to lower fast idle speed, if that's really the problem... (keep in mind that vacuum leaks, linkage damage, bent components, and misadjustments to the linkage can cause the actual fast idle problem, and that backing out the screw can simply be a cover for other issues that need to be repaired).
Advanced
Joined: Mar 2010
Posts: 78
Likes: 0
From: Houston TX
Fast idle speed screw is on the passenger side of the carb, below the choke linkage. The screw head faces forward. Back the screw out to lower fast idle speed, if that's really the problem... (keep in mind that vacuum leaks, linkage damage, bent components, and misadjustments to the linkage can cause the actual fast idle problem, and that backing out the screw can simply be a cover for other issues that need to be repaired).
What Lars said... Unless everything has recently be gone through with the carb and vac setup, given the age of the overall lacking of expertise of the Rochester's, I'd be very skeptical and look through everything closely.I know that on one of my previous car's Quadrajet, I set the idle to what should have been right, a few runs later it was off again, set it again right, then rinse wash repeat several times until finally it clicked in that thick head of mine that it shouldn't be so variable and erratic. The carb ended up needling lots of love, in spite of having recently "rebuilt" it - in fact, I believe that was one I ended up sending to Lars in order to get right and restore my sanity. Lars is the man!
Last edited by Ryoga23; Apr 24, 2014 at 02:48 PM.
