QWKDTSN Posted May 12, 2002 Share Posted May 12, 2002 Hey all.. me and my dad have been looking at my ignition and trying to figure out why it won't work consistently. Before, I wasn't getting any spark, and it was because I had the two black and white wires that go into the HEI coil reversed (oops). I'm not surprised, given that they're impossible to tell apart. So how exactly does this ignition work anyhow? My dad has no idea and I'm not much help. What we're trying to figure out is what kind of voltages we should be seeing on the TACH and BAT wires when the car is off, in the start position, and cranking. I've had the car pop and fire a couple of times but when I hook up a timing light it only flashes intermittently. I pulled a plug and grounded it out on the header but it never flashed once while cranking the motor over. I wonder if there's anyone in the San Diego area who wouldn't mind heading down here to help me out..? I'm just using the standard wiring harness and HEI, like the JTR book spells out. Quote Link to comment Share on other sites More sharing options...
Tim240z Posted May 12, 2002 Share Posted May 12, 2002 Dude, Try a bypass wire from the battery to the coil and see if that helps. At least that will narrow it down. Tim Quote Link to comment Share on other sites More sharing options...
QWKDTSN Posted May 12, 2002 Author Share Posted May 12, 2002 it seems like it has enough power to fire off one or two cylinders when I crank it but then it dies. when I crank it up it will pop once or twice immediately but then will just turn over on the starter. I tried hooking up a hotwire like you suggested but results were inconclusive. there are a few things that I am going to try tomorrow when there's more daylight to work with. it's probably something stupid Quote Link to comment Share on other sites More sharing options...
Guest greimann Posted May 12, 2002 Share Posted May 12, 2002 Trouble shooting these kind of problems can be really frustrating knowing that something that should be stone simple is causing so much difficulty. When ever I get into that situation, I step back and make absolutely sure that the basics are covered first. New cap, new rotor, plugs gapped at .035, each plug wire resistance tested. GOOD ground to the block. Once you have covered these basics, and I mean verified every parameter, then replace the unknowns like module and coil. Ignitions are really simple devices and I predict that one of your problems is a breakdown in one of the basics. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted May 12, 2002 Share Posted May 12, 2002 HEI PROBLEMS A common mistake when replacing the inner coil is to forget to transfer the ground strap for the coil. Leaving this strap off will erratic ignition especially under load. I hope this helps. Sunny Quote Link to comment Share on other sites More sharing options...
Mike C Posted May 12, 2002 Share Posted May 12, 2002 The biggest mistake with HEI is trying to run it with less than full voltage. Make sure you have bypassed the ballast resistor. With the key in the run position you should have 12v at the distributor. Make sure you are getting voltage while the engine is cranking as well. If not you can run another wire to the distributor from the unused terminal on the solenoid. The terminal was originally provided for points ignitions to get 12v on startup, then when you let off the key they went down to 9 volts or so to run so the points don't cook. Quote Link to comment Share on other sites More sharing options...
QWKDTSN Posted May 13, 2002 Author Share Posted May 13, 2002 Okay, I fixed it. The wire from the fuel pump switch was spliced into the wrong black and white wire (not the hot one to the coil) so I just unsoldered and resoldered it into the proper wire. Duhh Quote Link to comment Share on other sites More sharing options...
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