Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
This is my second attempt to get some help. Today, I started the engine, ran for about 10 minutes then shut off. No codes. Tested for spark at the coil, none. Tested the coil negative with test light, test light bright, cranked the engine and the light flickered. Re-checked for spark and now I have it. Plugged everything back in and now it starts again. What could be causing this.
All the distributer engines were gone by the time I started fixing cars, so my experience is very minimal.
Maybe you've seen this video from Scanner Danner & Eric the Car Guy?
With an intermittent issue like that check wiring terminals on the harness and look for chaffed wiring /bare wires. Also check ground wires (from block to battery and block to chassis. If wire terminals are green and crusty replace them. Load test each wire with wiring unplugged from pcm and all sensors and ignition control module (mounted to drivers fender.) Using a 4 amp bulb.
