Holley 4150 way to high idle.

[Cope]

Hi folks i need some help with my carb.

Car is a 1971 dart 318.
I just removed the dizzy to fab new kickdown linkage (not hooked up) and now I have an insane high idle, like 2,000 Rpm high (no tach).

Curb idle screw is not even touching the cam.
no matter how much timing I pull out I cant get a good idle?

Timing is around 8 BDTC but to even get where it dosnet sound like my engine is gonna blow Im at @ 10ADTC.

I have sprayed the carb with eletric parts cleaner and found no air leaks.

Both main and secondary butterflys are closed. I cant understand how with all the blades FULLY closed it can even pull that much air?

I just rebuilt the carb and it was working fine before I pulled the kickdown linkage and Dizzy.

It dose look like a lot of fuel is dumping out of the primary discarge nozzles but I never looked before so I dont have a base line to truly judge off.

Thanks for any and all ideas.

 

[AJ/FormS]

-Assuming you are correct when you say all butterflys are closed: Did the pcv line or brake booster line get accidentlly dislocated or cracked?
-Its also possible that the PV is ruptured.
-Curb idle screw and cam dont belong in the same sentence for 4150s
- with closed blades the nozzles should absolutly NOT be flowing

 

[rmchrgr]

I just rebuilt the carb and it was working fine before I pulled the kickdown linkage and Dizzy.

I would look there. Clearly something was disturbed or not put together correctly. Re-trace your steps, it's probably something simple. Maybe you reversed a gasket uncovering a hole inside the carb or something.

Kind of sounds like a vacuum leak. Cover the carb while its running, see what happens.

 

[TrailBeast]

I would look there. Clearly something was disturbed or not put together correctly. Re-trace your steps, it's probably something simple. Maybe you reversed a gasket uncovering a hole inside the carb or something.

Kind of sounds like a vacuum leak. Cover the carb while its running, see what happens.

I'd bet on this.
Totally sounds like a vacuum leak.

 

[Cope]

Dam I feal stoupid..

main butterflies were not fully closed....

My new throttle linkage was holding them open almost a 1/4 inch...

Gonna reset and see what happens...

Face palm..

 

[BIG-B-Barracuda]

I had the same issue, because I had replaced the base and gaskets of the carburetor/intake with thicker versions so because it was taller the throttle cable was throwing the idle off. Stupid mistake that I overlooked. Thank guys for the clear insight always turns out to be some thing small and simple.