Steve you are the Master!
Full write-up:
http://www.peachparts.com/Wikka/M103VacuumLeak
I tried everything mentioned on the thread and the only thing that really worked (and it worked very well) was to monitor the O2 sensor and use some carb cleaner. It was amazing how easy it was. If I sprayed it for just an instant at the leak the O2 sensor responded. If I sprayed too much in any direction the vapor would get sucked into the throttle body and alter the sensor reading. The trick was to shoot very small amounts and be a little patient. I started by unplugging the EHA and ICV, removing all the vacuum hoses and taping the nipples, and unplugging the throttle switch. Then I took a 3mm Allen wrench and changed the mixture so the O2 reading was about .1 volts. A shot of carb cleaner at the ICV and the O2 would hop up to .8 for a couple seconds and then return to .1. You couldn't hear any change in idle speed. Cracked bypass hose on the head side.
Also found the injector seal on #5 leaking.
Argon, propane, oxygen and water didn't do much at all. the stethoscope might work well for a professional but I just couldn't discern all the noises coming through it. After I found the leak I tried all these methods to see if there's difference and I couldn't find one.
After I repaired the vacuum leaks (temporarily until the parts come) I reset the mixture to be rich at .8 volts. Then I sequentially reconnected each of the vacuum hoses while the engine was running. When I removed the tape the sensor would drop to .1 volts, then I'd replace the hose and watch the sensor. Each time it went right back to .8. This gave me confidence that there were no leaks in the vacuum system or brake booster.
I reset all the fault codes and then set the mixture control using a duty cycle meter.
The car starts up much much smoother. When it was warm it could be a bit cranky at times. Now it fires up instantly.
Thanks for all the tips.
Robert