Turbo Biscuit

Indeed it was the module that must have cut out. Measured the amps on the OEM coil. 1.4A ac. With the PS60 coil, it's drawing 2 to 4 A ac ! I was mistaken about the resistance. It was good the whole time, I looked at the wrong spec. on the crane PDF and just got mixed up. I guess this means that the coil is fine with 9 or 12 since nothing in the Crane datasheet says anything about a resistor. I'm sure MSA just tells you that you must use the resistor in order to save your module. I have a capacitor I just haven't popped it on yet, I'll let you know if that fixes it after I get the new coil going. Thanks for the info!

I know I haven't fried the ignition module because it still works with the old coil. Perhaps it wasn't the coil that gave it up, but the transistor module that cut out from too much current. I think I saw a thermistor on the module board. It may have over-current protection on it. I will buy a resistor this week and test the coil again with the resistor on it. I was trying to figure out equivalent components to rebuild the ignition module in my last thread, just in case it did burn out in the future but was unable to identify the values on a few things.

Ah, this makes sense. I wish I had known that there were two types before! Thanks and merry Christmas to you too

Well MSA's website says to "retain and use stock ballast resistor". I figured since there was no stock ballast resistor I wouldn't need one. I'll grab a resistor and see if I can't salvage the coil. So if my stock coil runs without a resistor, what's the point of a nice 'performance' coil if I'm going to have to limit the voltage to it?

Revamping the ignition system on my '78 280z. Everything but wires and the coil have been replaced, the motor has been timed and is dead on. The problem I'm having is with the old coil there are misfires pretty frequently. Not so frequently that the car will stall at a light or that I can't idle at 800, but enough to where it bothers me. The misfire only appears with the timing light on the coil to distributor wire, it doesn't happen on any of the plug wires. I ordered a crane PS60 coil and installed it and the car ran like crap, the tach jumped when it started and then died (not permanently, just didn't work with the coil). I did an ohm check on it and the secondary coil was infinite, so I returned it and got a new one. I put the new one in today and the car started stronger than ever (although the tach still died), it sounded beautiful. Then it just stopped. The coil pack was warm, and the resistance on the secondary coil read 2k less than what it had before I installed it. Then I heard plugs firing inside the cylinder head for awhile after the car stopped. Now it won't start at all with the PS60 coil. Seems to me like I fried it. The 78 has no ballast resistor for the coil (it limits the current in the transistor module), only a resistor in the interior wiring for the tach. My stock coil runs at about 13Vac when the car starts, and as it starts to warm up, the voltage drops to 11Vac. Has anyone had any issues with this? Does the crane coil need a ballast resistor (2.2kOhm?)? Would I be better off buying a PS20 or 40 coil since it has the same specs as the stock coil? Thanks!

Hey all, new to Hybridz, been working on a '78 280z since March now. Had some good times and bad times but have learned a lot! I am having some issues with my ignition system. I've got the engine to purr pretty well, but it does miss randomly. The timing is dead on at 800 RPM, but it's still missing and I'm getting some crossfire on cylinders 1 and 2. When I swap wires 1 & 2 the crossfire goes away but the motor still misses. I can't tell which cylinder is missing, I'll leave the timing light on each cylinder for quite awhile and don't see any misses (even though I hear them), but when I hook it up to the coil-to-distributor wire I see the misses. I've replaced everything except the coil and wires (coil in the mail, had to return it to MSA because it was DOA), which it seems likely it would be one of them. However I was wondering if it might be the transistor module. I opened it up and would like to replace all the semi-conductors and capacitors. The board has been dipped in a "tamper proof" epoxy, but it melts off pretty easily. I was wondering if anyone has done this before I go reinventing the wheel. I couldn't find a datasheet for the power transistor, and the zener diode codes on the board aren't specific enough to find a direct replacement. If anyone could shed light on this I'd appreciate it. Thanks! Also, the coil on the 78 280z doesn't have a ballast resistor (there is a resistor for the tach down the line in the circuit), so I'm getting 12v AC on the coil. From my understanding the module limits the current on the '78 so as to eliminate the need for one, is this true?