FiTech EFI system

I had my EFI unit 30002 all set up on my basically stock 318 that was freshly rebuilt (cam is essentially stock, maybe a notch above; it's built to be a driver). The unit ran fine through the winter when I drove it a total of about 15 miles to and from the various local shops to get aligned, vert top installed, etc. Then last month, it kept blowing one of it's internal fuses and the car wouldn't start, so I had to ship it back to FiTech for them to replace the ECU. I reinstalled it last week, and the car runs strangely. It idles fine for about 3 seconds, then falters, then idles fine, then falters, etc. I have a 15 second video clip with the sound here (along with a shot of my handheld), if anyone has time to listen to it and tell me what you think:



I have reset the learn, adjusted the IAC to roughly 3-6, and adjusted the AFR to 13.0 since I took this video, but nothing has helped. The problem seems to alleviate a bit (but not completely) once the engine warms to full operating temp, but while warming up and/or sitting at a stop light, this is what happens. With the weekend here, I'd like to play with it a bit, but of course, tech support isn't open again until Monday, so I'm hoping for some suggestions here. Anyone else have this issue or know what to try?

Also, fault codes 74 and 36 were showing when I took this vid two days ago, but since I have reset the learn, only code 74 shows, if this helps.