Help, need gm expert I have a 1999 blazer the engine cranks normally but doesn't start right up and when it does its slow to come to normal idle,have replaced the fuel pump,rotor cap and button, plugs coil, there are no codes reading the fuel pressure is abt. 62 with key on and 56 running, took the ignition module and had it tested and the say it works.Also checked back lash in timing chain and that is normal.