There is also the RUSEFI out there that is insanely configurable/DIY.
Ya, the guy who started that was a Festiva guy, there's some amazing technology out there and he's utilizing it. Last I checked it was pretty well developed.
Both of mine have IAC function problems, and I was wondering what coilpacks were worth. Is there a modern replacement for the VAF and IAC?
Jack Byrd
Coilpacks, I'm not exactly sure how much better they are - but you could get full control over your ignition system. No lossy distributor cap/rotor, and you can program your own timing curves instead of the fixed mechanical vacuum & RPM/Centrifugal weight setup in the stock distributor. Get rid of that annoying OEM ignitor. You can add in a more modern knock sensor, too.
Modern systems could utilize a MAF instead of a VAF, and would be much more free-flowing. Though you could eliminate it altogether and use a MAP sensor system called Speed Density
Idle valves - there are a plethora of options, mostly re-purposed OEM units from other cars. I think there were guys who were making billet housings to adapt a GM or Jeep idle valve for universal applications, able to be installed with some new hoses