I have a mildly built 406 with a 750 CFM Edelbrock carb. My problem is after I swapped the heads over to Brodix aluminum heads. The car will idle in park or nuetral at about 1100 to 1200. Once I put it in gear the idle drops between 700 and 800 this is a little to low and the car wants to pull threw the brakes a bit. If I give it gas(while in drive) to about 900 everything is fine. When I adjust the idle so the car idles in park or nuetral at 900 or so once I put it in gear the idle drops drastically and it wont run on its own.

I have the timing set at 38 degrees at 3000 RPM, what can I do so the car doesnt want to die? I hate having it idle at 1100 or so while in park or nuetral.

 

Well for the most part, a built carb'd motor will have to idle a bit higher to keep it running without stalling when it gets put into gear. What cam are you running? I have a 218/224 duration .495/.502 lift 110lsa comp cam, and I have to set the idle pretty high in park (say around 1300-1500; tach no worky) to keep the car from stalling in gear.

Just bump your initial idle up a couple hundred rpm and see what happens. It might be something you have to deal with. Oh and just out of curiosity, what is your initial timing set at?

 

I have no idea what cam is in the car, I bought the motor from a speed shop. The guy who owned the motor went with a different setup and the guys at the speed shop rambled out some numbers. I know its a decent sized hydraulic cam.

Honestly I dont remember what I had the initial timing set at. I havent touched the timing in over a year.

 

thats just hilarious..

sorry, but i had something similar to that.. i swapped my cam and heads(brodix) and it wouldnt go back down to idle with my edelbrock 800.. haha.. i never got it fixed though.. cause i switched to a 750 mighty demon..

 

Well, if it does have an aftermarket cam in, then you'll have to deal with a high idle when warming up. Don't worry though once it's in gear and warmed up, you won't have to worry about it idling high, unless you like to put it in park at red lights

 

That is my problem, even when the motor is warmed up the idle stays the same.

 

yea i am having the exact same problem but it isn't as built as yours but i have a rather large cam(xr282hr) and i can't get it to idle in gear without it being at like 1100 rpm in park. it sucks i don't know how to fix it.

 

You don't fix it, you accept it as a way of life. A large cam just won't idle at a factory speed.