I've got a 260Z 2+2. I changed out the old distributor (mechanical) and installed a used electronic ignition from an early 280Z. It has 7 wires. The car runs - better than before, but the tach doesn't work. Somewhere on the internet, I've seen directions for wiring, but I can't find them anymore. The Haynes & Chilton manuals aren't very helpful for wiring directions.

Also... anyone know how to troubleshoot a tach? Now I'm worried I might have fried it trying to get it to work.

Thanks.

First off, loose your ballast resistor. Join the wires going to it. All that does is allow the engine to have 12v all the time instead of just when starting.

That may do it.

If you had already done that, then check to make sure that the black white wires going to the coil (which feed the dizzy) are NOT reversed. If they are, the dizzy won't work although the car will start and run.

2¢

Originally posted by zoom240

I've got a 260Z 2+2. I changed out the old distributor (mechanical) and installed a used electronic ignition from an early 280Z. It has 7 wires.

What parts of the electronic ignition did you use? I'm considering taking part of my 280z engine and using them in my 240z project. This is one of them.

I got the parts from a used parts guy in the Houston Z club. I can't remember the exact parentage, but based on what I remember & reading Chilton's, I believe they are from a 75-77 280Z. I've got the distributor with the stock pickup, the ballast resistor (3 taps) & the electronic module.

The rest of the story is that I used to have a wiring diagram. I installed the distributor/module & it worked fine... kind of. Smooth idle, pull to high RPM's, etc... But occasionally at high RPM, the tach would go crazy. I'd get artificially high RPM readings & the car would bog down like the timing was off. I could push in the clutch, turn off the ignition & then restart the car -- high RPM's would go away. So it was electrical. Drove me crazy.. but the tach worked after a fashion.

I decided to go back to mechanical distributor & bought a remanufactured mechanical distributor from Nissan. Installed it. Never could get the timing right. Car would run... I drove it to work & back twice (about 80 miles round trip), but really bad performance. Blowing smoke, strong smell of unburned gasoline & very rough idle.

So, I just put the old electronic unit back in. Smooth idle, runs nice. Don't seem to have the occasional bogging down, but my tach doesn't work so can't tell.

And that's the rest of the story. With a 28 yr old Z, there's usually more to tell.

I'm going to try & post a jpg of my wiring diagram, but as a newbie... we'll see if it makes it.