I have a 91 z28 with a 10 to 1 383 topped with a first fuel intake. I recently installed the EZ efi setup retro kit. It works like the normal setup they have with their throttle body except it's for existing fuel injected setups with 8 injectors. Basically its a wiring harness that plugs up to all of your existing gm sensors, a wideband o2 sensor and the ECU. I also replaced the ignition with an MSD 6al box, blaster ss coil and billet distributor. The car ran great for 2 days and then began shutting off at random. The car fired right up again with the turn of the key but it would happen again and again. I triple checked all of the wiring and found everything O.K. I also replaced both the coil and MSD 6al box and still the car was intermittently shutting off while driving. It runs clean without any hesitation or sputtering and then dies. I sent the ECU back to FAST fuel injection and they checked and tested the ECU and said it's O.K. Could it be the distributor? thats the only thing i haven't replaced. I'm at a loss, i checked every connection and can't find anything.