92 vette stall and no start
 

I have a 92 Vette. It failed SMOG and the tech said the ECM was not sending input to the EGR. GM rebuilt the ECM. Came back and passed with flying colors. Soon after, it started to act up. Intermittent stalling and complete no start. I tapped on the ECM and the car stalled. I sent the ECM back but GM said they couldn't find anything wrong. The tech who put it in did not plug in the ECM plugs all the way. I ensured all plugs where snug and secure when reinstalled. Car still acted up. Intermittent stalling and complete no start, again. Checked spark to plugs with a spark tester, none. Removed coil wire from OPTI. With spark tester installed between coil and OPTI, it started and ran. HMMM. Checked coil wire, all good. Checked plug to coil, all good, no frade wires and cleaned all plugs with contact cleaner. Reinstalled, car started. Moved coil plugs and wires, car shut down. Issue found. The coil was an after market coil and only had 1 tab lock and the plug would come loose and disconnect from the coil. I reinstalled a stock coil, no problems since. I know this was a long dragged out thread, but I hope it helps other Vette guys. Sometimes it's the simple things that we over look.