97 4g63t swap isue

ok own a 97 galant purchased it used. wiring was brutal to say the least. purchased a used 99 eclipse ecu and engine harness installed it but not getting any spark. I cant figure out why!! not sure if the tach signal needs a medium signal supply or if its just not wired right. wired it up according to schematics but still nothing. im getting power to the coils but again no spark what so ever. when I purchased the car it ran but really crappy. one night it over heated and never started again. compression is low on 4/3 cyl so head gasket will be replaced. however cannot figure out why no spark?!?!?!?! 97 galant 4g63t swap 97 ecu/w 99 wire harness both from eclipse gsx also have awd conversion done parts from a 97 gsx eclipse. again ran fine/ needed tune. over heated then would never start again. replaced thermostat, ecu, wiring harness fual pump rewire just no spark?!?!? any ideas? know its hard just curious? also the mpi and fuel pump relay from97-99 harness are different. wired what I thought was correct would this prevent spark if not wired correctly? how do I convert a 99 harness to 97 ecu??? at my whits end about to crush this sucker and move on

Do you still have the galant harness? It's easy to rewire that for the 2G ECU and sensors. I myself wanted to go with a 2g harness but there were too many differences for certain things.