93hatch306

Help. Converted a 93 LX from 4 to V-8, donor car was 90 GT. Had to get 93 comp. & engine harness to work with chassis harness. Ran good for 8 months, then voltage reg. went bad, killed computer. Replaced computer 2 weeks ago, ran good for 9 days then car dies. Fuel pump doesn't cycle when ignition is turned on, code scanner will not communicate. What did I miss? Aftermarket electric includes MSD 6AL, Pro-M MAF, 30# injectors, Mallory 255 pump and PA Performance 130 amp alt.