are you ready for a long one cus its done my head in for the last week

ok first i swoped over from a t2 to a t3 turbo all went back together ok as far as i am aware then we changed the injectors to beige injectors but what i wasnt aware of they were the wrong ones (bought off ebay and shouldnt have taken someones word for it should of checked part number) anyway put them in without looking at them all went in ok went to turn it over and it wouldnt turn over tried but wouldnt quite go so then checked the part number and found out they were the wrong ones so put the blues back in and it was the same so started checking the usual things spark and such like took one of the plugs out turned it over looking for a spark and then it fired up on 3 without the 4th plug in so thought it must have been blockage or something so put the plug back in and again it wont start then proceeded through all 4 plugs and it did the same on them all starts on 3 but when 4th plug is in it tries but wont quite go
any ideas what this could be

i have tried putting the plug in whilst running on 3 and soon as the plug gets close to the hole it cuts out(dodgy i know )

i was told the erst manifold gasket was diferent so swoped that but same have fuel

all injectors seem to be working all plugs have spark

i am wondering if putting the wrong injectors in might have blown the ecu at the mo trying to get hold of an ofac ecu now

but if you can help in any way let me know as i am starting to run out of hair to pull out