Ignition control module (ICM)

[Zed Head]

The ballast is there to protect the coil and the old module. If you swapped in a 78 or later coil, or a GM external HEI coil, you could get rid of the ballast. You'd have the full HEI setup.

Are you going to describe the module testing machine? I'd still like to know what it does and who has them.

[z_ya]

Well I do have a 78' 280Z and the coil just came with the ballast so I went ahead and kept it there so can i get rid of it? And that testing machine I used is at work which is a local parts store with green shirts I can't remember exactly but i believe it is a borg warner made machine and it just tests ignition modules and a number of other things with various different connectors for each different module or part. I'm not sure what other parts stores have them i'd think all would but that's the tester I used.

[Zed Head]

Thanks. I didn't realize that there was a testing machine for modules, although it makes sense that there would be since the inputs and outputs are simple.

Of all the threads and posts I've seen about "how do I tell if my ignition module is good or bad" I've never seen anyone suggest taking it to the parts store to be tested.

I just bought a dome lamp from someone in a green shirt.

On the ballast - do you mean you got another, replacement, coil and it came with a ballast? The stock 1978 system didn't have one, I believe, I could be wrong. You need to get a coil that can handle higher current if you want to get rid of the ballast.

If you want to match your GM HEI module and don't mind a coil that looks kind of ugly, get an external HEI coil, from a mid 70's GM 6 cylinder pickup or Nova. I'm sure you have some in the store. You'll need to put new ends on the wires to fit the coil, but you'll have a set-up optimized to work together. You'll also have to build a mounting bracket.

Edited May 31, 2013 by Zed Head

[z_ya]

Yeah, to test the 280Z module was a pain but take it in and they will do it. But back to the matter at hand. My car being the 78' 280Z would I be fine with removing the ballast? Is that what is causing my tach to jump when i rev it up quickly, and making it a bit of a chore to start?

[Zed Head]

I added to my other post... above, about the ballast.

[z_ya]

Did not see it up there, my apologies.

[z_ya]

I remember seeing the MSD Blaster 2 was the recommended coil of choice for this swap. The one that was with the car when I first purchased it did not have one that I can remember, me not knowing the difference between a good price and a cheap part back then I picked it up from a online wholesaler and it was just a generic "diamond" brand coil with the soap bar ballast so I just hooked it all up together. I will check out the suggestion of a mid 70's coil. Our msd 2 just went on sale and with it being on sale my discount does nothing haha. I have not heard of any bad things happening from running a coil without a resistor other than just burning it up, is there anything serious that can happen if I try and run the coil without the resistor or am I asking an obvious an silly question?

[Zed Head]

Actually, I ran my 76 coil with the GM HEI module and no ballast for a while and it didn't overheat and there was no damage. No guarantees on your diamond brand coil.

On the jumpy tach, I had to install an extra condenser on the negative post of the coil to get my tach to work right. I think that the HEI module might generate more "noise" on the coil negative post. Might be worth a shot, a typical radio suppression condenser might work.

[z_ya]

Okay, I had followed the diagram from earlier to hook the HEI module up, I originally had the black and white wire (ECU #1) was left were it was when I bought the car it was placed on the positive terminal, and the blue tach on the negative. This was with the ballast hooked up. It ran and started but I go to start it just earlier and nothing happens. I have no spark. Ran through the wires and it appears now that both my - and + are continuous. So did my coil get fried? Or did I hook something up wrong and have it magically work twice before it telling me to bad?

[z_ya]

Turns out the HEI module I had was faulty or I had damaged it somehow as it did not pass the high rpm range. I got another one, I did not buy the msd 2 though (maybe that is the problem?) I'm gonna wait till tonight and try this again but I will bypass the ballast. Now you did say that the #1 ecu wire goes on the negative, with that wire producing a +12v wouldn't it go on the positive terminal?

[Zed Head]

Do you have a good ground to the mounting hole metal? The modules are sensitive to bad grounds. The metal of the mounting holes is one of the ground circuits.

Both sides of the coil have 12 volts when no current is flowing. Pin 1 attaches to the negative post.

[z_ya]

I'm confident with my ground that I had used, And is the pin 1 to negative just for this swap? Cause I've always had it hooked up to the positive and that's where it's at now with my OEM ICM. If so then I'll do it I just don't want to ruin something that will cost a decent chunk of money. And yeah after thoroughly going through all three of my books (chilton, haynes, and the FSM) I have checked the pickup the coil an all that. But for some reason last night I could not achieve spark through the OEM ICM either and have no idea why. But after unhooking everything and hooking it back up with the OEM it started an ran.