Metro Posted November 5, 2005 Share Posted November 5, 2005 I've been chasing this problem for about a month now. I've got nowhere, even with a totally different fuel injection system and wiring. By weak spark, I mean I have to hold the plug cable within a few thousands of an inch of the block to see a tiny spark. I've replaced the coil - tested with 4 different ones, 3 used and a new MSD blaster 2 Replaced the plug wires Replaced Cap and rotor on the 81zxt and 76 280z dizzy Tried two seperate EFI systems, stock '81zxt with CAS and '76 VR dizzy with megaquirt-n-spark extra. What I know: with the original 81 280zxt plug wires, I get little to no spark with new MSD heli-core wires, I get little to no spark with my old '76 solid core wires I get a decent spark, but this kills my ecu (both the stock 81 ecu and the new megasquirt). Causes the ECU to reset everytime the coil fires. The coil sees 10.5 volts at the lowest while cranking So it would seem to be a problem somewhere else in the car - not related to the distributor, the coil, the wires, or the ignition module. I've cleaned all connections to the battery and added extra grounds to the ECU and motor. With megasquirt I'm using a new harness that I've created which takes power from a different source than the 280zxt harness did. Basically the connection to MSnS is all new in every way. The only part of this system I haven't replaced the battery, but then I don't think it could be bad. It holds 12.65 volts and 10.5 volts when cranking and the starter doesn't have a problem turning the motor over. The only thing I can think of I haven't tried, is to wire the coil directly to the battery. If anyone has any ideas, let me hear them, I'll try just about anything. Quote Link to comment Share on other sites More sharing options...
260ZRED Posted November 5, 2005 Share Posted November 5, 2005 I'd do exactly what you said, or at least measure how much voltage the coil's getting when ignition is ON. Very strange.. edit: I see you already did that.. Quote Link to comment Share on other sites More sharing options...
Metro Posted November 7, 2005 Author Share Posted November 7, 2005 Well, fixed, sort of. I'm not sure why I couldn't get a decent spark with Megasquirt V3 and the VB921 coil driver, but hooked up to a GM 4-pin HEI module it works great. As for the 280zx efi, I think I fried the ignitor on for the 81 280zxt coil. Quote Link to comment Share on other sites More sharing options...
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