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View Full Version : Aftermarket HEI dizzy help 360


scdetector
11-04-2015, 04:47 AM
I need some help/advice... Ordered a HEI distributor off Ebay for a 85 Dodge, the one that requires a external coil. Installed the dist, wiring is simple 2 wires coming off the dist +/- goes to coil and 12 volt wire to the coil + from the ignition switch bypassing the resistor, no factory wiring was used. The truck would fire and try to start as long the starter was turning it, when the key was released at the point of starting it would cut off, voltage to the coil was constant 12 volts even releasing the key from the start position, just to rule out voltage I wired the coil + directly to the positive side of the battery and got the same result. I checked all the wiring several times, firing order and grounds as well. We used a 12 volt non resistor universal coil. After the fact I noticed the description states "not in instructions" to use a low primary resistance coil between .5-1.0 Ohms, the ohm reading on the coil we used is about 3.3 which is high, could this possibly be the issue? I reinstalled the factory dizzy and it started on the first try without issue and reset the timing. Not sure if anyone has experience with these distributors. Plan on trying another coil with a lower primary resistance like the Blaster 2 which I think is .7 ohms. I've run plenty of GM HEI ignitions in my Chevys but the coil is on top of the cap so there was no need for a external coil.

JVMopar
11-04-2015, 08:30 AM
Check the ground of the distributor.

John Kunkel
11-04-2015, 02:16 PM
What year/model vehicle is this? If it has the factory ignition switch with the IGN1 and IGN2 circuits be aware that each circuit is only powered in one switch mode.

IOW, IGN2 (usually a brown wire) is only powered when the switch is in the Start position and shuts off in Run. IGN1 (usually a blue wire) is only powered with the switch in the Run position and shuts off in Start.

Sounds like you have your setup wired to the IGN2 circuit which shuts off when the key is released from Start to Run.

scdetector
11-04-2015, 03:00 PM
Thanks, as far as the distributor ground, I thought it was grounded by the block or do I need to run another ground? It is a 85 Dodge truck. The 12 volt wire from the coil was run directly to the battery just to test the distributor as a last resort. The dist has a red/black wire that goes to the +/- of the coil and the 12 volts goes to the coil + , basically a 3 wire setup

JVMopar
11-04-2015, 05:03 PM
Since you wired the positive directly to the battery you've eliminated the ignition switch completely, and ensured the positive side of the circuit is fine.

So it has to be the ground side of the circuit that is open when the key is released. The distributor base may not be getting a good ground to the block.

I'd try and... Well I'd just leave the factory ignition in there. It works and is simple.

But if you want to run that HEI I'd try running a jumper wire from ground to the dist. base and see what you have.

scdetector
11-04-2015, 05:37 PM
Thanks again, it's a friend's truck and he wanted to swap so I jumped in to help him out. I'll ground the distributor and try it again this weekend, may have a poor ground from the battery to the block which I'll check.

scdetector
11-09-2015, 11:02 PM
Well, wanted to wrap up this thread, it was indeed the primary resistance of the coil. We used a MSD Blaster 2 coil (.7 ohm) and the truck runs great with the new HEI. The stock coil was around 3.0 ohm...