I have a 95 blazer, followed factory service manual trouble shooting guide. It took me down to vcm-a or wiring on one guide, and icm or wiring on another guide , replaced both components with known working parts, still no fire. I pulled entire engine harness at this point , and have found a total of 10 bad spots in harness ,8 of which will affect various sensors. Two are no fire scenarios. One is a knicked ignition wire right next to
A knicked engine ground. The other is the no fire culprit for sure. This is the ignition wire that feeds the tach side of the icm, and the crank shaft position sensor. The wire had been severed about a foot and a half out of the fire wall by a sharp point on the engine or body. I am currently renewing my entire harness, and trying to come up with a cheap bullet proof wire wrap to prevent future problems.