BlueBloodOval

Same problem with 2001 Chevy 1500 truck with 4.8 litre engine. Truck ran fine then was stolen. Towed home as battery and relays were missing. Ignition lock housing was drilled out between the housing and key tumbler joint, looked like a 3/16" drill bit. Current tag also ripped off. (Oakland Calif. go figure). Replaced battery, relays, new GM ignition lock housing with key and tumbler. Assembled tumbler with key several times with different gear tooth combinations until we had off, rotate to ignition on, rotating key more to start position. From key off position rotate key the opposite direction to accessory position. No other tooth count combination will allow this full rotation of key functions in both directions. Will assemble steering column and wheel after truck is finally running. That shouldn't cause a no run condition? Crank with no start, dead fuel pump now replaced we have fuel and spark. It will start and run 3/4 of a second with app 6-8 cylinders firing in order then dead. Can repeat start and dead 20 times thinking air in fuel system requiring purging air out. Heck return fuel line loop should cure air in system problems. On those short start run bursts the oil pressure rises to 60 psi. The "SECURITY" dash light is on and blinking. I haven't checked fuel rail pressure as well run a scan tool at this time. This a "SECURITY" "passlock" computer fuel shutdown the problem on this 2001 truck? Been told newer trucks 2004 up required dealership computer clearing $$$$? How to clear it if the computer is the problem? Already tried "ignition on and off three times within 10 minutes". Already tried other "clear the computer" tricks and ideas with zero luck and running again. The low oil pressure "cut out" sensor a no run cause problem? Where is this low pressure cut-off switch located to bypass jumper it? At whit's end! Parked dead on the street (not Oakland) three months fighting this truck daily after work in the dark and rain before the cops have it towed. Thanks in advance. "CJ"