Quadrajet on SB 350 chevy idle question (1 Viewer)

[Norcalcruizer]

I have a Qjet on a stock SB 350, the idle seems to occasionally move from 700 rpms down to about 600. If I bump the throttle for a quick moment it comes back up. Does anyone have any idea what I could try to make it consistent. Other than this it runs great, and no cold start issues with electric choke. The only thing I did do was adjust the cold choke idle down from about 1400 rpms to around 1000. I just felt like 1400 was excessively high for warming up the engine.

Thanks for any information you can provide.

-NCC

 

[B y r o n]

How long has it been since the carb was rebuilt or cleaned? If could be you've got a little crud inside that is momentarily blocking one or more of the jets. Try running one of the fuel system cleaners through a tank or two and see if the problem still exists.

 

[Norcalcruizer]

No idea how long it has been since a rebuild. Runs very good overall, I also noticed a bunch of grime on outside of carb linkage, I am going to hit it with some carb cleaner to help free up all linkage parts. What should idle be set at for manual transmission? I have it set at 700 rpms, does that sound about right?

 

[handcannon]

It's been a long time since I've done much with a carb, but it sounds to me like you are on the right track. After reading your post my first thought was crud on the linkage gumming it up. To me it sounds like Byron is spot on with what you can do for your first shot at the problem. And if that, and spray cleaning the linkage, does the trick for you, then that would be an inexpensive fix.

Don