Stalling and dipping idle is a common issue in these motors and you can apply a few tricks to help. I can help if you like but contact me via PM as the topic is not that simple and I need to know what your EFI system is capable of doing. I've solved this issue many times both in stock DME as well as other EFI systems.

I need to know any mechanical changes that may have lightened the drive-train, things like lightweight flywheel or clutch package or changes in cams or valves.

Also, does the EFI have a idle control valve? If so how well can the valve be controlled? Read up on this section of the EFI documentation as it's also important to getting back to idle properly.

If you need some guidance PM me and I'll try to help.

Add more ignition timing in the rpm areas below where the idle is set.
Example, if the idle is set at 800 rpm and ignition timing is set at 10 degrees
try set the ignition values below 800 to 15 or 20 degrees.

Well, it's been a long time since I've updated this thread. Quite a lot has happened since my last post.

In summary, I drove the car a decent amount last year. No problems, ran well, etc.

At the start of winter, I decided to give the ECU control of the ignition as well as the timing. I machined a steel timing wheel and bought a set of LS2 "truck" coils, pulled the engine, and made a bunch of changes to the wiring harness. I was just about ready to put the engine back in when I decided to go "all in" and turbocharge the car.

I had bought a used set of OBX stainless headers a few years ago, and I already had a K26/6 turbo from when I owned a 944 Turbo.

I'm going to go start a new thread over in the 911 turbocharging forum to document the project. It's basically going to be a "budget" project, so feel free to gawk as I throw away money buying cheap/used parts. I'll probably also buy tooling to make some parts that will end up costing substantially more than what the part would have cost me. It'll be fun!