Hey guys,

84 T/A, 355, CCQjet. My high choke idle is currently set to about 2400RPM. That's really obnoxiously loud with my current exhaust set up and was wondering how I would lower it to around 1800-1900 which is amazingly more quiet. This is normally my summer car but as we recently sold our other vehicle, I am having to drive it this fall/early winter. Normally it wouldn't be that big of a deal however I need to let it warm up before driving now that its getting colder it or it'll die in gear...and letting it warm up for 4-5 min or more just gets abit annoying. Anyway, just need to know how to lower the choke idle. Any help is greatly appreciated!

 

With the engine warmed up, manually put the high idle cam weight to the raised position - to do this, you'll have to open the throttle slightly, raise the weight, hold it in place, and let go of the throttle. The return spring should hold the weight in the raised position.

Now adjust the high idle speed screw. It's located below the weight. There is an illustration of it here, https://www.thirdgen.org/forums/carb...e-rebuild.html , Figure 6C1-7. Counter-clockwise lowers the idle speed. If you adjust it to 1800-1900 when warm, it'll be well below that when cold before the choke starts to open and the high idle cam drops.

Also, if your choke pull-off ("vacuum break" in the sticky lined above) is properly adjusted, when you first start the car cold, it should be on the highest high idle cam step, then drop down one when you tap the throttle. This should also limit the high idle speed when cold.

The system works amazingly well when properly adjusted.