Weird starting issue. Ever since my ECM was rebuilt I've been having hard starting. Motor will Crank for few seconds then sputter while still cranking after sputter cranks for another few seconds then fires up. Occasionally it fires right up like it should with in less then a second. If i swap ECM's out to another one programmed to truck never have a starting issue, touch the key fires right over. Is this an ECM electrical issue or something else in my starting system. Both computer perform equally the starting is only thing different between the 2

 

Almost sounds like you answered your own question.