flyrc100

This has a 350 Engine with an aftermarket HEI Ignition. I quit on me the other day, and I have determined I am losing spark as soon as I let go of the ignition key. While the Starter is engaged, the engine will start, as soon as I let go of the key, and the key cylinder falls back to the "run" position, it dies instantly. I am checking basic spark function with a Timing light. It sounds awful but if I keep the starter engaged the engine will roar to life and take gas/ revs up like its healthy. The Timing light is flashing away blinding me. Let go of the key and the timing light goes dark instantly and the engine stops immediately. The BATT wire to the HEI is cold when "off", and goes hot when I turn the engine to "run", so that seems to be working OK. Im checking the Batt wire with a test light.
I have no idea what to make of this. Engine seems to be timed correctly, no backfire or spitting. Does anyway have any ideas on what is causing this or how to troubleshoot?

oldcutlass

The reason your engine is not running when the key is released is because you lost the 12v supplied in the run position. Most often people run a 12ga wire from the IGN terminal in the fuse box. Check to see if maybe you kicked it off or there is a blown fuse adjacent to the terminal.

flyrc100

Yes thats what I'm getting. I used the original coil wire for the Batt+ and apparently its a resistor wire. I need to change it out to 12 gage non-resistor. Its been running like this for a year, but maybe the wire has degraded over time. Thanks for the advice, I was really stumped as to what was going on.

oldcutlass

You cannot use the resistor wire, the HEI must have full voltage to operate correctly.

flyrc100

I found a DYI vid and a guy showed were to pick off the Fuse block to get good 12v+ (IGN). So I ran some 12g wire, and Magic! It started right up. It had a small miss off idle and thats gone too. Owner happy, thanks for the input.

oldcutlass

Glad you got it sorted out. Now you need to get your timing set correctly, the stock settings are n/a because the hei has a different mechanical curve.