POScamaro198

I purchased a 94 lt1 Camaro and cant seem to get running Its getting spark and fuel pressure I tested the injectors with a noid light and it is not flashing I tried putting another pcm on it and did not fix the problem I checked the firing order and is good I checked all fuses and are good I tried spraying carb cleaner in the throttle body but will not run its backfiring through the throttlebody it has a new optispark installed the security light on the inside is on but not flashing im not sure if it turns off as the car starts up or not I purchased the car not running im debating on switching over to carb if I cant seem to get running I rather keep the fuel injection any help please