I have a 1998 GMC Sierra & it isnt firing properly, there is a orange spark jumping between the coil wire, and the coil.. I swapped the coil out with another one and it has the same problem.. I recently changed the coil too.. problem still exists. does anyone know why? also its the 6cyl vortec 4.3 engine.

 

does the coil need to be grounded to the truck?

 

Try a new coil wire. It may have bad insulation and is shorting out.

 

already swapped the coil wire out with one from a blazer.. it works perfectly fine on it but does the same on my truck..