Engine/Idle problems

I have a 98 Eagle Talon TSi. I just had my head rebuilt. I can't get it to hold an idle. If I keep it above 3,000 RPM, it runs fine, but the minute it goes below that, it sputters and stalls. I'm curious as to what might cause this. I checked and replaced all the vacuum hoses, all the timing marks are lined up to a "T," and cleaned the throttle body. If you have any ideas what might be causing this, I'd appreciate the input.

isc

Thanks, I'll give that a try. I've tried many other things without any of them working (to include disconnecting the battery to reset the ECU).