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Hello, I have been chasing this issue for over a year now. 96, F150, 5.0L V8, with MSD 8227 coil, new Ignition module (non-Motorcraft), reman Napa ECM, coil primary ohms .9, secondary 5500. Trucks starts and runs for about 20 seconds. Coil power + checks ok and - checks ok using a nonLED test light, the light does not flicker. Test the - side primary again and tests good, test for spark and now there is spark, test light method. Put the coil ignition wire on and truck now runs fine for the rest of the trip and day. When there is not spark, I have also tested spark function by back probing pin 1 on the ignition spark module and a test light, the coil will not spark. I have checked continuity of the pin 1wires between the ECM plug and the module and this is good, also moved harness around during this test. The only part I haven't replaced is the distributor hall sensor. What should I check next, do not have a scope but I do have a fluke 88.
