Roger, Actually, so far everything is working out very well. If what you mean by “limp mode” is the sequential ECM defaulting to batch fire, then yes and I’m going to stick with that. Makes life a lot easier in my opinion. The ECM will still go into closed loop under these conditions and behaves like my 1227065 batch fire ECM. I’m using the later ’86-’87 Buick turbo sequential ECM (1227148). It has much more chip and scan tool support than the earlier ’84-’85 Buick turbo sequential ECM (1227059).
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Yes, that's what I was referring to. I'm not sure why you aren't pushing to get the sequential working, though. I would think it would be much more efficient than the batch fire. I can see where it would be beneficial for the use of a pressurized engine, and maybe that's what you're ultimately after.
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I’ve got the knock detector and ESC working, and even have a scheme so that I can “dial in” the timing advance and fuel mixture independently right from the dash. To do this I’ll be using two ECMs. One ECM for fuel and boost, and the other for ignition.
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Whoa! Talk about a wiring maze! I'm guessing you've figured out how to fool the "ignition" ECM as far as throttle position, and you could use the output of the O2 sensor for both ECM's, (am I close?) The fuel mixture was already addressed using the 10K pot in place of coolant temp, or have you come up with something different?
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I just have to mount the turbo in place and fab the exhaust. But I’m afraid I don’t get things done as quickly as I would like.
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I wish I could get things done at record pace, too, but my personal plans always seem to get pushed onto the back burner, and it's now looking like they may get delayed an additional year, unless something changes in the near future. (I'm in the Nat'l guard, and am not at liberty to say what might delay things that long. <hint, hint>)
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How are you coming along with your supercharged EFI project?
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Manifold fully modified/fabricated, still playing with different brands of "production" fuel rails to see what can be used effectively out of the salvage yards. Got a bit side-tracked, as I ran across a great deal on a '70 Swinger with a 198 in it for $75. I get the engine & trans, and the rest goes to a work-mates 16-year old son for a 440/auto conversion. Still in search of an axial type supercharger....you got one in your back pocket I can get cheap?
Bob D

Roger, The reason that I don't go with sequential is the crank trigger, cam position sensor hassle. Just not worth the trouble in my opinion.
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DOH!!! Sheesh, I should have figgered that one out on my own. Completely forgot about the crank trigger stuff.
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Using a separate ECM for ignition won't require too much wiring. Unless I'm mistaking the ECM only uses RPM, the signal from the knock detector/ESC and perhaps the TPS to determine timing. I could be wrong here but will find out soon. All of the wires for ignition that went to the first ECM now go to the second one instead. Besides wire is cheap and bundles nicely.
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Well, I was thinking along the lines of what.....25 wires eminating from each ECM, and you'd have to do something with each one, even if only cap them off so they don't ground out. I suppose you could actually remove them from the ECM connector. Hmmmm.......it just occured to me that now you have a redundency to the vehicle. If one ECM fails on a road trip, it's just a matter of swapping the needed wiring over to the other on-board unit. Not bad, Bob.......you design airplanes, too?

Something you might want to think about, should your initial plan fail. Might the software in the ECM use the MAF input for a dual purpose, such as computing vaccuum?
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P.S. If your wondering what happened to the text in your post when you quoted me it was because I originally wrote it in word and then inserted it using Ctrl V. Guess I won't try that too often!