260Z Tach Connector

[shankeroid]

Having Tachometer Issues and need to troubleshoot.  Finally got the Tach loose and out the hole.  I've tried everything....having a helluva time getting that connector loose, only enough room for 1 1/2 hands.  What's the trick?

 

[SteveJ]

IIRC, it's squeeze on the sides and pull.

[heyitsrama]

What sort of tacho issues are you having?

[shankeroid]

Thanks for the replies.  I tried the "squeeze the sides" thing, I probably didn't squeeze hard enuf.  Difficult to squeeze with 2 fingers and also pull out with the same hand.

Ok, so I went back out to try again. Squeezed for all I was worth.....NoJoy.  To be clear, I tried the "far", the "middle" and the "close" sides squeeze together with pulling the connector.  Was able to work a second hand in there for the "pull."  Nuthin.

[shankeroid]

The tach issues are:

Has worked flawlessly for the past 2 years I have owned the car.  One day, the needle was lethargic and didn't react to quick accelerator blips. Needle did move, but very slow.  Also, never hit an appropriate high RPM (approx 3K or higher.) When engine shutdown, needle would slowly settle to somewhere between 500 to 1500 RPM.

Able to tap on the tach to get it to settle to zero.  Multiple tries after tapping to zero with similar results. Plenty of info on 240 and 280 tachs with lazy pointers, not much on the mighty 260!!

 

[heyitsrama]

Interesting that it randomly gave out. Did you change anything to the ignition system?

im guessing you have seen this thread?

 

 

[shankeroid]

Thought I had seen all the threads, but not this one.   If I can just get the doggone thing out......

 No changes to the ignition system.  Ignition is an MSD-6A with adapter and all wiring to distributor and coil are intact.

[SteveJ]

41 minutes ago, shankeroid said:

The tach issues are:

Has worked flawlessly for the past 2 years I have owned the car.  One day, the needle was lethargic and didn't react to quick accelerator blips. Needle did move, but very slow.  Also, never hit an appropriate high RPM (approx 3K or higher.) When engine shutdown, needle would slowly settle to somewhere between 500 to 1500 RPM.

Able to tap on the tach to get it to settle to zero.  Multiple tries after tapping to zero with similar results. Plenty of info on 240 and 280 tachs with lazy pointers, not much on the mighty 260!!

 

The 260Z tach is essentially the same as the 280Z tach, including the wiring. Don't forget to check the resistor in the circuit. It's over in the passenger footwell area.

[SteveJ]

9 minutes ago, shankeroid said:

Thought I had seen all the threads, but not this one.   If I can just get the doggone thing out......

 No changes to the ignition system.  Ignition is an MSD-6A with adapter and all wiring to distributor and coil are intact.

Considering the 260Z has a Transistor Ignition Unit (TIU), I would call an MSD-6A a change from stock. Is the car running right? If not, that could mean the TIU was not unplugged. That could mess with the tach, too.

By the way, a friend got his 260Z tach serviced by Bob's Speedometer (https://www.bobsspeedometer.com/), and he was pleased with how the tach operated after that.

[Zed Head]

Search "280Z tachometer" and you'll find pictures of the plug out of its socket.  Might give you the confidence to pull harder.

My tachometer used to stick when the weather got warm.

The capacitive discharge ignition systems are well-known for causing tachometer problems.  MSD, Crane, etc.  Might be worth your while to reconnect the old ignition module and see if the problem goes away.

[shankeroid]

SteveJ, where exactly is the resistor in the footwell area?  And the TIU?  See pic.

The car is running great, no problems there. Got the pic of the plug outa the socket, I am continuing to wrestle with it.

[Racer X]

5 hours ago, shankeroid said:

Thanks for the replies.  I tried the "squeeze the sides" thing, I probably didn't squeeze hard enuf.  Difficult to squeeze with 2 fingers and also pull out with the same hand.

Ok, so I went back out to try again. Squeezed for all I was worth.....NoJoy.  To be clear, I tried the "far", the "middle" and the "close" sides squeeze together with pulling the connector.  Was able to work a second hand in there for the "pull."  Nuthin.

The connectors on Datsun Z cars can be very difficult to separate. Keep trying.

Edited June 1, 2021 by Racer X