so after i did the 2bbl -> 4 bbl swap (weiand street warrior intake and holley street avenger 570 cfm) i loved it. tho as of late ive noticed some problems.

Problem: Usually if i slam it the tranny will kick down a gear and accelerate (just like it would when i had the 2bbl and when i first swapped). now it is bogging down and not dropping a gear. I can slam it and it just almost feels like the car is struggling horribly. once the rpms start to rise it comes to life but it takes a bit.

The car will drop a gear and scream at lower speeds (20mph-ish) about 50% of the time. usually anything under 70mph the car would drop a gear

i was thinking maybe electrical problems and i threw a mallory 6al in there. didnt seem to do a damn thing. response still seems sluggish.

I messed around with the kick down adjustment today (finally had a day off work....64hr weeks suck). heres the site/pdf for my carb http://www.holley.com/0-80570.asp
i tried taking the at adjustment screw in and out and didnt see a difference at all

in short a lot of the time i try and slam on it and it just feels like its falling on it face.

brand new air filter, fuel filter, spark plugs, cap/rotor, wires, and fuel lines. fuel line reads a normal about 5-6psi

thanks

 

"adjustment screw"? The 66 Mustang kickdown has no adjustment screw, it's a cable-operated kickdown using a lever attached to the pedal throttle rod. Changing from 2V to 4V should have had minimal effect on the kickdown, although it may have required adjustment. The kickdown is purely mechanical, so even if your car is only running on 5 cylinders it should still kick down.

Adjust the throttle like this. First, make sure the carb primary throttle opens all the way, have a helper hold the pedal on the floor. Remove the throttle rod 9A702 at the carb end and adjust until the carb opens all the way exactly when the pedal hits the floor. Keep the pedal down, and adjust the kickdown cable 7A187 at the threaded-rod end until it is fully pulled when the pedal is on the floor.

This diagram shows the kickdown. 66-68 V8 used the kickdown of the 65 6cyl.
http://www.gerlecreek.com/images/65-66mustaccellink.jpg

 

thanks ill give that a shot. tho their is (according to holley an adjustment screw hence the reason i looked at that first)



sry all i had on me was my phone

 

True, but only on a 69-up with a rod connected to the "Transmission Kickdown Lever". On yours, it's doing nothing.

 

ah ok. i was thinking the stop lever stopped any throttle depending on where the kickdown screw was at