I am having problems with starting the LS-3 in my SLC. Engine turns over fine. Fuel pressure is 58 psi. I have ignition spark and signal to the injectors. No codes in the PCM. The engine turns over but will not start. After spraying a little bit of starter fluid into the intake, it starts and runs rough at first and then evens out. It continues to run as it should. If I turn off the engine and immediately try to restart the engine, it will not start. Anyone have any ideas as to what the problem may be?