need some answers
Gm tech2 you can command certian injectos to pulse. and you can hook up a fuel preasure gauge and watch for fuel presure to drop after you command that injector on. This is key on engine off. And it is always a good idea to check spark with a spark tester(like $3-$5 tool). cause you could have some other problem that would cuase a coil pack not to fire

