The engine blew on the '99 blazer a few yrs ago, and I found a 2001 which was running before I got, so I put it in and it turns but not running, checked spark ok, checked fuel ok, not sure but should I have got the ECM and wires when I got the engine? I have a newer Jeep for my kids mom so we are giving to my 15yo son but still have the same problem. I read somewhere I have to program a 2001 ECM to VIN# but from the looks of the ECM online the wires or Pins don't match... soooo??

 

*Moved to '2nd Gen Tech'*

 

My truck has an 01+ Block and its a 1999, did you swap your upper and lower intake, injection system, and pretty much everything electrical?