Surging Idle when Hot Outside

[thom4782]

The idle on my e-gas S surges between 600 and 1000.

When its cold outside, the idle is steady. The hotter it gets the more the surging occurs. For example, the idle is rock steady at 50 degrees. At 80 degrees, it's moving up and down between 600 and 1000 every few seconds. It will seem to steady up at 700, drop to 600, pop up to 1000, resettle at 700, and then start the down-up cycle all over again.

Any idea why this might be happening? Most importantly, why does this dependent on outside temperature? The MAF is new. It was happening before and after I replaced the MAF.

Thanks