During my search to cure M103 warm-start leaness and stumble, I discovered that the EHA has the ability to "learn" and "remember" richness settings.
This is changing all my thinking about warm-start leaness problems.

What I observed it doing:
1. I richened the EHA base setting by turning the adjustment screw CW a bit, as referenced in several posts herein. Sure enough, on the first try, the mixture richened during initial turnover and open-loop warm-up; started good. When the system went closed-loop, the EHA current went negative a bit (-3 mAMP) to lean it back out - all was good.

2. But, when I started the car later, the EHA actually remembered that it had been leaning the mix a bit, and as soon as the car started, it adjusted the mix to -3 mAMP. This caused an even leaner condition for the first few seconds, and the motor stumbled as bad or worse than before.

So, it would seem that adjusting the base setting on the EHA can affect the crankover richness (when the EHA is turned full rich) but as soon as the engine fires, the EHA will compensate back, even while still in open loop.

I experimented a bit; sure enough, wherever you set the EHA, when it goes closed loop and sets a current to achieve proper mix, it remembers that current and goes right to it after a warm start.

Sooooo, how does one achieve a bit of richness during the first few seconds of open loop operation after a warm start? I hate to be out-thought by a 20 year-old computer.

DG