moparstables
Well-Known Member
What would be the correct rpm when the carb is on the high side of the fast idle cam?
I have a 440 bored 40 over four speed with a holley 850 double pumper with an electric choke non acYear/engine size/carb type/at or stick/ ac/? etc.... More info needed.
The problem I am having is that when I get the car started and warmed up sometimes it wants to idle at 1500 rpm then other times it idles at 1000. I am thinking that it might be idling off of the fast idle cam. It is hard to see the fast idle screw to know if the cam is all the way off of that screw. I had the same problem with the old motor. This is a new motor and I put on a new performer intake.Depending on other variables like cam grind........... What are you looking for exactly ? High idle is not as important as the standard idle speed which for a stock engine would be in the 650 - 850 range
It idles fine sometimes then other times it idles fast but also sometimes if I tap the foot feed it will idle down and sometimes I have to let out on the clutch a little to pull the motor down to idle then it will stay at the correct idle rpm.With the engine not being stock, there is no right answer to your question. How is the idle speed when warmed up ? Is it steady ? The engine should idle with the butterflies almost closed.
Thanks I will read this and try it.OK here is an article on tuning. There is a procedure to set timing and carb . It is the same for any make of engine. Timing is always first and then carb adjustments.
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