I've been watching this thread - just haven't been able to really jump in yet.
I've tracked down the last patent holder (I think) to Actia Corp. in Elkhart, IN - but I've not gotten anything out of them yet. I may have to stop by next time I'm in the area...
Mr_W, any chance you can read that Motorola number a couple of times, write it down, and post it? My eyes aren't what they once were, and I'm not sure I'd get a good read off of that picture. If you get me a number, I can start washing it through cross-reference guides I've got access to and see what I can dig up.
Oddly enough, injector drivers are really the only "failure" I've heard of in RENIX, save one unit (that's the one that Boatwrench sent me in trade for a good one. I want to do FA on it later.) I've heard of two failed injector drivers (now three,) and I've got one of the old units stripped of its case and out in the shop somewhere.
The problem with knowing anything significant about these things is simple - it's a non-standard pre-OBD system that was designed by an overseas (to us) automaker and built by a company that does avionics (Bendix/King.) It was only used for four years - 1987-1990 - and the company that used it over here is defunct (AMC, purchased by ChryCo in 1988. ChryCo was purchased by Daimler-Benz around 1993, and has recently changed hands again...) So, it's work just to track anything down. I'm working on it tho - I'm rather fond of the RENIX setup, and I prefer it to OBD used in later years.
See if you can give me an accurate read on that Motorola number, and I'll see what I can do with it. I don't guarantee results, but I'll do what I can (if I can at least identify the part and get specifications, we can come up with a workaround...)