272 idle question

[rmtz24]

well the cavalier is officially running with 272 cam pretty well, i did have a question though for you computer guy's.... the car was tuned by a good friend of mine with an increased idle speed of 950rpms, when i first start the car cold it's got a mean sounding lope then when it starts to warm up the lope goes away, the idle speed isn't changing that much during this... i'm curious as to what's causing this change in sound?
Thanks

[Superdave]

Can you get some datalogs?

When it's in open loop it'll run rich which can cause it to lope pretty hard, mine won't even idle on it's own till it hits closed loop because of that. There are a few adjustments that can be made to the spark advance table to get it to lope all the time at idle though.

Ask your friend for the .bin file he used, we should be able to take a look at that and see why as well.

Here is mine trying to idle at 950 RPM

http://media.putfile.com/950-idle-4-5--vacuum