I am having problems getting consistant idling with my new setup. its a pretty radical high compression,solid roller 383, i have to have it idling around 1000-1100 RPM to keep from stalling at stoplights. I have been messing with the idle stop screw and as soon as i get it to idle right, the next time i go to run it its either idling too high or too low. I have my TB blades cracked open quite a bit and i think thats what it causing my problem with inconsistency. I have been trying to set the IAC counts according to the Accel book (i have the gen 7) and havent had much luck. who all has drilled a holes in the TB blades, and what size bit should i start? I have a BBK 58MM TB. Thanks

Chad

 

are you using a air foil on the TB? you might want to enlarge the hole on the air foil, first.

 

no im not running an airfoil, i dont know if you can even run an airfoil on a bbk TB, can you? i never checked into it, but it doesnt look like you can, or would want to.

Chad

 

Don't the BBK TB's have an airfoil built in or am I thinking of another brand?

Myles

 

its really slim and smooth, if memory serves, it was one piece. Air foil would serve no purpose.

 

well correct me if im wrong but the stop screw is useless in this case, because the iac will adjust no matter what to get the idle at what is programmed in the pcm. Why not just fix the idle tables in the pcm?

 

You have to adjust the idle table in the pcm....the screw will do you no good.

 

You only need to drill a hole if the IAC counts are maxed out. Like if the counts are above 150. Then you need to let more air in. If you let it in through the blades it will feed the cylinders unevenly. It's best for the air to go through the IAC passages. So don't drill the hole in the blades. Look straight into the front where the idle air goes in. It doesn't go straight through. It routes air down and around the valve. Drill the hole there so you can see straight through. This will let air bypass the valve but still go into the IAC passage of the intake. I did this for my AS&M TB. Start with a small 1/16" hole and then test drive it, check the IAC counts, see if they're still maxed, drill a little bigger.

 

Thanks for the info guys... I was just going by the gen 7 book, just a quick rundown of what it says "select the minimum IAC position vs. coolant temp table. set the value at normal operating temp to 5%. Monitor the IAC position value and adjust the throttle blades to bring the Actual IAC position value to 6%. To lower actual IAC position value, open throttle blades, to raise, close the blades. IF the target idle speed does not match the engine idle sped when the IAC position is set, the throttle bores are distorted, a vacuum leak is present, or the throttle blades need to be drilled." I dont know if this is the same with the stock PCM or not because i dont know much about it and im still learning the gen 7. Anybody familiar with what im talking about with the gen 7? thanks

Chad