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?

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!

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?

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!

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?

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.

Just replaced the voltage regulator. Radio now works fine and no acid condensation on the battery case after driving.

I checked the voltage regulator. It is charging at about 15 volts at fast idle and up to about 17 at 2500 RPM. New regulator has been ordered! I,m guessing that the stereo hase some kind of circuit protection against excess voltage. Probably explains the moisture (battery acid) by the vents on the battery after driving!

I just installed a Sony CDX-GT550UI stereo in my 71 Z. Unit works fine when the vehicle is not moving, but shuts off temporarily whenever the engine is under load, such as acceleration or going uphill. It comes back on when coasting or under no load. Initially I had it wired to a circuit controlled by the ignition switch, but changed it to being wired directly to the positive terminal of the battery when I first encountered the problem. Could the problem be a bad voltage regulator? The voltage regulator appears to be very old and the alternator looks to be recently installed.