greenmachine

Thanks for the quick response. Mine broke in half and it is just clamped onto the remaining length; not very secure!

Did you find a source to replace the plastic fitting?

Frank you are not quite correct. The car has a 280ZX breakerless electronic ignition, which uses a 3 wire tach. Got the problem resolved by cleaning the back of the ignition module and the distributor body where the module mounts. The completed a good ground and the tach works fine now. Zed Head, see above for what fixed my problem. I also posted the question in the right forum once I realized my error in posting here. Thanks to both for your thoughts!

SteveJ you were right! It took me awhile to figure it out, but the problem was with grounding. I finally realized the tach signal comes from the negative terminal of the coil, which, since it is negative, must also be grounded. I cleaned the back if the ignition module and the dizzy body where it attachs. When it was making a good contact with no corrosion the tach works perfectly!

Oops! Should have posted this in the electrical forum. Can anyone advise how to delete this?

I tried grounding directly to the negative battery terminal. No change in behavior!

I have installed a 3 wire tach in my 71 240Z with stock L24, 280ZX ignition, and MSD Blaster 2 coil. I spliced the positive and ground wires into the original 4 wire tach harness, and ran a wire with a 2200 ohm resistor in line from the negative terminal on the coil to the tach. When I start the car the tach indicates what appears to be the correct RPM for 3 or 4 seconds, then drops to zero. Revving the engine results in a reading on the tach which seems to be too high (for example, about 2800 RPM at 60 with stock 4 speed and 3.36 axle). Also, whenever an electrical load is applied (turn signals, 4 way flasher, heater blower, headlights, any or all) the tach needle jumps to a higher RPM and back continuosly. Bad tach or did I miss someting in the installation?

I have insalled a 3 wire tach into a 71 240Z, stock L24 with 280ZX ignition and distributor and MSD Blaster 2 Coil. I spliced into the original 4 wire tach harness for positive and ground, and ran a wire with a 2200 ohm resistor in line from the negative terminal on the coil to the tach. When I start the engine, the tach indicates what seems to be the correct idle speed for 3 or 4 seconds, then drops to zero. Revving the engine gets a reading, but my seat of the pants fell is that the reading is too high (indicates about 2800 rpm at 60 with stock 4 speed and 3.36 axle). Also, whenever any electrical load is turned on, such as turn signal, 4 way flasher, or blower motor, the tach needle bounces to a higher RPM and drops back to whatever it read before applying the electrical load. Bad tach or is something else needed in the installation? All thoughts wil be appreciated!

Thanks! Glad to hear it works with your setup.

From what I have heard that tach will not work with the ZX ignition. Thanks anyway!

I have a 1971 240Z, stock and original L24 with 1983 280ZX dizzy, E12-80 module, and MSD Blaster 2 coil, and no ballast resstor. I am installing a later model 3 wire tach. Do I need resistor inline with the wire from the coil? If so, what ohm/amperage is needed? I appreciate any and all advice!

Sorry! Should have been posted as a thread, not a blog.

A couple of days ago my '71 first series 240Z refused to start and run. Came with a Jacobs Energy Pak when I got it. Appears that the switch for "Computer" or "Conv Ign" is bad; it has 3 large cracks in the switch housing and "crunches" when switched from one position to the other. Decided to remove the Jacobs and replace with something else. When doing this, I discovered that my L24 has a D6K82-01 distributor which I think is from a later (1983?) 280ZX. The module looks like an E12-92 in that it has 2 terminals on top and 2 on the side. I cannot locate anything on it stating it is an E12-92; just IGM-08 and made in Japan. Nothing indicating Nissan or Datsun original equipment. Wired the distributor/coil, eliminating the ballast resistor and the car starts and runs fine (well at least after I couldn't get it to start until I reconnected the wire from the coil to the distributor!). I have had the car up to about 75 mph. Acceleration seems fine with no indication of pre ignition or other timimg problems, which I thought I would have if it is an E12-92 or aftermarket equivalent module. Questions: 1. Can anyone verify what year/model the dizzy is from? 2. Any idea what module I have? 3. Just what good things was the Jacobs Energy Pak supposed to provide?

My 1971 240Z had a Jacobs Energy Pak in it when I bought it. A couple of days ago, it died and wouldn't start. Apparently the switch for "Computer" or "Conv Ign" has lived it's full life; there are 3 large cracks in the top of the switch and it kind of crunches when switching from one position to the other. Anyway, I decided to remove the Jacobs and install a Petronix or something. While doing this. I discovered that my L24 does not have the stock distributor. It has a D6K82-01, which I believe is from a later model (1983?) 280ZX. The module LOOKS like an E12-92 in that it has 4 terminals, 2 on top and 2 on the side. I cannot locate anything saying it is an E12-92, just IGM-08 and nothing identifying it as a Nissan or Datsun part. Questions: Can someone tell me what year/years and models used the D6K82-01 distributor? Any idea what module I have? What was the Jacobs Energy Pak good for? The car starts and runs fine afer wiring the distributor and bypassing the ballast resistor (Well, at least after I reconnected the coil to distributor wire when it wouldn't start!). I have had it up to about 75mph with no problems, and acceleration seems fine with no hint of pre ignition and good acceleration; I thought this would be a problem if I have an E12-92 or aftermarket equivalent module

Thanks for the tip! Apparently this has been a problem for a while before I bought the car as part of the battery tray has been eaten away and there is some corrosion on the firewall. Fortunately not too bad and looks to be easily cleaned up and protected.