2001 Jeep Cherokee cranks slow to start

Have a 2001 jeep grand cherokee limited 4.7. Have changed fuel pump and crank sesnor. Car when cold cranks but very slow to start sometimes have to turn key back and try to re-crank usualy after that it starts fine. Check engine light has come on with no code set. After driving and turning off and then re-starting after a couple minutes it starts fine. If youe let it sit for more then a few minutes its slow to start and runs very rough until you get up to speed.