problem with ignition coils or bad cylinder or hopefully bad harness

[Maka187]

Hi guys just wandering if anyone can help got a series 1 r33 gtst and having problems with coils first it was gap of spark plug but now when i test each coil by removing plug while on nothing changes on 1 cylinder? so i took harness off sanded ground amd where its grounded put it back on qnd it worked, but because the spark plugs were not gapped i had to take off harness again .when i put back again cylinder 1 not sparking, i have cheap red coils but i tested them in other cylinders and working fine.So is it the harness you think or is it the cylinder shat itself.any knowledge wiuld b appreciated thankyou.