Will not stay started

Just dropped a fresh engine in my car listed above Mk4 2.0L, non turbo gasoline. While I had the engine on a stand I replaced all sensors, cam, crank, coolant, knock, both 02, vehicle speed, new fuel pump. Fuel filter seems to be flowing, I have 35 lbs before the regulator. Timing is correct, verified once again before I sat down to type this. Car starts then shuts off immediately there after, almost like immobilizer issue. Hooked it to my vcds light and that is showing no codes, immobilizer light is not present in either the vcds scan or dash light. Car starts, runs great for a 30 seconds or so. Then shuts off, doesn't sputter like its fuel starved, shuts off like someone unplugged it. Turn the key and starts right up again. Yes, the throttle body has been aligned using block 098. Suggestions anyone? I can post a vag scan if needed. Thanks guys