'65, 289, holley 4600 (1850-2) carb, c4 trans, msd 6t ignition, msd coil and msd magnetic trigger. Did final adjusts on a rebuilt carb, set idle, set pump, set primary valves, set timing and final adjust on idle. Has great throttle response at idle but go to put it in gear and it stalls. Increased idle still dies, decreased idle still dies. Curb idle set at 1600 rpm. Was running and driving 3 days ago on initial rebuild settings on carb. Final adjustment was done because I had an off idle stumble after rebuild and thought it was in need of setting the pump. Have checked both pump and power valve both seem to function fine. Any ideas?

 

What's the lowest it will idle without being in gear? you need to get the idle back down to the 700's or so. It sounds like a vacumn leak /too lean to me. cause at 1600 rpm you're running off of the main circuit. get it idling out of gear first then look into the in-gear problem.

 

factory spec is 1600 fast idle according to the manual for an auto transmission and 600 in drive same specs are on the sticker on the valve cover. Have had the engine down to 700 and tried thenup to 2000 and tried both times and on the way up and down it dies. Have had valve (mixture) screws from where it drops idle speed to where it doesnt matter if you screw it out any further it wont increase idle speed. Same story. Vacuume lines are new and doubled checked. New vacuume modulator as well.

 

My car only idles at 1600 when the car is warming up. Once it is warm, the idle should be between 700-900 depending on your specifics.

 

^yeah - that sounds high...

I agree - look for lean condition (with the engine running/air cleaner off) slowly move your hand until you almost completely cover the throat - if the idle picks up - rich it out!

No change? Spray for vacuum leaks.

 

1600 is way ,WAY to high, You want like 700 to 750.Sounds like some readjustments are in order and maybe some timing.I had a similar issue on a 69 chevelle with a ls7 and ended up being a combo of timing and carb adjustments.

 

Yep, some confusion on the idle speed. Once your car is warm it no longer needs the fast idle speed of 1600 rpm. It shoul kick down to 700 to 900 rpm and idle smoothly. Get it to this condition first. Idle mixture, timing, valve lash, compression, curb idle speed setting all affect the warm idle speed. There is good advice in an earlier post about coveringthe carb throat with your hand and listening for idle speed increase/decrease. I've seen all kind of weird things cause vacumn leaks over tte 30 + years I've been turning wrenches. (Like leaking brake boosters leaning out 1/2 the engine)