1800 RPM Idle after tune-up?

[FishNinJay]

Well, I fixed my problem, sort of. My rig doesn't die when idling anymore. In brief, I have a 327 SBC, w/ Edelbrock 4bbl 1406 carb. Took the carb off to spray it clean (not rebuild), blow out with compressed air, reinstall. Fixed electric choke. Plugs looked black/sooty. Would start up, and idle nicely, but then stutter and die, or stutter and roar back a bit to idle, but eventually die.

Last night, I replaced the distributor cap, rotor, and plugs. (AC Delco R44TS). Roars to life now, and keeps running now. I hooked up a digital timing light with tach, and at idle, it's going 1600-1850 RPM!!! (in park)

In drive, it settles down, and sounds like a much lower and more reasonable RPM. Shift into park, and it revs back up.

I gap'd the ACDelco plugs at 0.40 and replaced the cap with an MSD cap/rotor only. Re-Used the old HEI coil, ignition module, distributor gear, plug wires, etc..

What the #@*& is going on now?!?!

Few days ago, I also replaced the air filter, but not the PCV (yet). There is an opening in the air filter housing that is uncapped right now. Need to either cap it, or connect it to a sealed oil filler cap (closed PCV system?)

As always... THANKS.

 

[64 Yoda Pilot]

I guess you have backed the idle adjustment screw all the way out and the rpm is still high. If so it sounds like the choke is stuck in the wrong position. the electric control could be the problem or check the mechanical choke linkage where it contacts the idle screw. you can unplug the choke to trouble shoot the electric control.

My 1st thought anyway. Good luck.

 

[inkpot]

I guess you have backed the idle adjustment screw all the way out and the rpm is still high. If so it sounds like the choke is stuck in the wrong position. the electric control could be the problem or check the mechanical choke linkage where it contacts the idle screw. you can unplug the choke to trouble shoot the electric control.

My 1st thought anyway. Good luck.

Yea, what he said. On the passenger side of the carb, there is a stepped wing (cam) that holds the throttle plate open when the choke is operating. It may be out of adjustmen enough to cause a high idle, even when the engine is warm and the choke wing on top should be wide open. John

 

[FishNinJay]

yes, I backed out the idle screw until it was wobbly and about to fall out!

I didn't mess with the front mix screws, cuz I'm unfamiliar with them.
Maybe I didn't wait long enough to let the choke open? I fixed the e-choke
a few days ago by running 12v to it from the wiper circuit, and when I turn
the key to start, the e-choke on the passenger side of the carb get's warm
(actually hot!), and the valve opens up after a few minutes. Didn't check it
today, but I'll look into it tomorrow. Assuming the e-choke is ok.. any other
ideas? Could this be timing? I didn't hear any knocks or pings? I'm also
reading about the PCV and possible vacuum leak?