Stevo9090

Good day my rb20 single cam has recently started giving me trouble to start. At cold start it will hard start till it finally do or doesnt where the rpm gauge goes all the way up to 4000rpm and red lights blinks on both the brain and the dash(under the power kickdown light) I had change oil, plugs, airflow, fuel pump, checked all injectors and rail regulators Been searching the net to find solutions and haven't came up with anything. NEED URGENT HELP