Well that is really weird, the Mass-flo system uses the A9L ford ECC and they are supposed to be nearly bullet-proof (although awhile back at ffcobra.com there was a rumor that supplies were running out so I got one on eBay just-in-case!). I would assume your electrical system is otherwise OK? Still plenty of power to turn the starter, horn, headlights? If the ECC sensors identify low voltage the system will shut down. The check engine light going out before you try and start the engine indicates major failure - low voltage, open relay, blown fuse. Check system voltage and all fuses, relays and even though the light goes out, try grounding the self-test sensor lead, turn the ignition on and see if the light gives you any codes. Email Chris at mass-flo, he will often call back on weekends even, he is very good at customer support
