First off Im running a 383/T56 combo with a MAf.

I cant get my car to idle. If I lightly hold the gas at 900-800 rpm, its fine. On its own, the idle will dip to say 500 RPM rev up and then die.

Im just getting into burning chips. So aside from the basic stuff, working on the idle is my priority.

For the first chips I was raising my stall saver settings, this really wasnt helping. Then I adjusted the idle closed loop target RPM vs coolant temp settings. I basically set the all to 950 RPM if the were previously any lower than this. Is the "target" RPM really where is tries to settle at? I know on Diacom it shows up as "desired rpm". im wondering if Im adjusting the wrong setting.


As always, any help/advice is appreciated greatly.

 

I'd shoot for an idle at 800-850 rpm unless you have a huge cam. It sounds like you need to open up the throttle blades a little using the throttle stop screw (driver's side of TB) since it sounds like the IAC isn't able to open up enough to keep the idle speed up. Yes, target RPM is the same thing as desired RPM, just a different nomenclature (name).

 

Is this how the desired idle works:

The screw should be adjusted to the desired idle (say 800 RPM). the as long as the motor is at that idle, the computer will not adjust. If the manual idle is at 700 and the desired idle in the computer is set to 800, then the computer will try and compensate? If the computer adjsuts, is it only for a short period, then it will go back to the manual setting and adjust back to the desired, thus causing sparatic idle?

 

Yes, the computer will bring the idle speed up from the manual (aka: minimum air idle) speed up to the requested idle speed. Nope, it's always trying to keep the idle speed at what is being requested, so in this case it'll use the IAC motor to compensate. If your idle speed is fluctuating at 800 rpm, maybe try 850 or 900 rpm and try again. If that doesn't work, then you probably have a vacuum leak or something else is wrong. Have you bumped up the spark advance where you'll be idling at in the main table? That helps some since it gives more vacuum which might help smooth out your idle if nothing else is wrong...