working on a 2000 4.3 silverado
DTC P1351 Ignition Coil 1 Control Circuit High Voltage
wouldn't start so we scanned with efi live and got that code....
replaced the coil cranked and still wouldn't start....tried again directly after and it started. put everything back together went to start it and it did the same thing as before. stuck a screw drive in the end of a plug wire and tried to start it and it made an arc, put the wire back on and it still wouldn't start. tried the screw drive trick again and now now spark....whats goin on? its like theres a loose connection somewhere...but where

 

check the white wire goin into the coil, its known for breaking inside the insulation right at the connector