Here's one for those who like to swap modern EFI's into things that might not use a transmission, or way to feed the ECM a corrected Vehicle Speed Signal. In my case it was a boat, and I tested several of the latest GPS speedo converters out there. However the wave pattern was always wrong for my late model engine, so the ECM wouldn't recognize the pulse signal.
Then I found this GPS-50 from Dakota Digital.
Has a built the built in GPS antenna, plus an accelerometer that kicks in if sat signal is lost. I've used one for 2 years now, mounted under a 1" thick fiberglass dash. Amazing little box that will pump out about any wave type or resolution you'll every need. Just one wire to the ECM VSS signal, 12v hot, ground, match up the pulses per mile and your done.
I don't work for them, or receive a dime from DD. Just like their stuff cause every time I've need some sort of special adapter, they say "we make that." And when ya like to DIY crazy builds like myself, it's cool to speak with someone who understands what your actually doing..
That's my tip of the day.