Hard start concerns when cold
I have a 2005 Excursion that has trouble starting when cold. The FICM outputs are good and the batteries tested good. It usually cranks for at least 5 seconds before starting up and runs like **** until it reaches operating temperature. Once warm it starts fine. Now the kicker is when I have the block heater plugged in overnight it will start up immediately like it never had a problem. It will still run a little off until it reaches operating temp. I run 5w40 synthetic oil. Any ideas why the long and hard cranking issues? Could it be the glow plugs or GPCM? I recently replaced the FICM as it was going bad. The starting issues never got better and remain the same as before the FICM replacement.