Car stalling AGAIN, Updates- none of them good. Options

[rjames]

Drove around for 30 minutes in 80+ degree weather. All arterial roads, so several stop lights, etc. No problems until I was almost home. Car stalled when I stopped at a light. RPMs just dropped to zero. Was able to start it again with a little difficulty and had to keep my foot on the gas to keep it from stalling out again. Power seemed ok though the rest of the way home (I think). It stalled once again at a stop light a couple of blocks from home and then again when I pulled in the driveway. I let it sit for 30 seconds, started it again and it idled just fine. Rock solid at 1000 RPMs. Pulled it into the garage where it sits now.

Prior to today the car has been running and idling perfectly since I went through the FI parts last year, which included installing a 123 distributor, new CHT sensor, a newly rebuilt mps (calibrated for correct afr on my engine), new vacuum hoses, NOS throttle body, rebuilt injectors, new fuel pump, valve adjustment and timing.

I haven’t checked the AFR since last year, not sure why it would change though.
It’s a ‘75 so the fuel pump is in the front, so I can rule out vapor lock I think.

Anyone have ideas as to why it would be stalling?

[rjames]

Since I started this post, I'll give an update on where things are at, and also respond to the other two people who are having similar issues.

Got the new ignition harness from Jeff. A work of art. Installed it yesterday and spent an hour re-tuning the mps. I thought I had it dialed in, but I realized that at idle the AFR was way to rich at ~11.2. Although the part load AFR was good at ~13.5.
Maybe this was part of the cause of the stall all along? Maybe it was a combination of old wiring and an idle that was too rich? Maybe nothing is fixed and it just hasn't stalled yet?

So I'm back to trying to dial in the AFR and the problem I'm running into now (what what I ran into before) is when I set the AFR set for partial load (~13.5) using the MPS inner adjustment screw, the the idle AFR ends up being too rich (~12.5).
So I then try to lean out the idle AFR using the throttle body air bleed screw and the ECU adjustment knob to a point where the idle speed is at 900-1000k and doesn't hunt, but that puts me at 12.7 at best. I see others at 14+ AFR at idle.
What am I doing wrong here? (IMG:style_emoticons/default/confused24.gif)

As far as the others who are having stalling issues... start a new thread.
I say that not to be a jerk, but because there's a lot of potential causes that you are seeing similar symptoms, and going through them all will not only derail my thread but it will make it harder to troubleshoot your particular situation. (IMG:style_emoticons/default/smile.gif)