Could be you just need a tuneup.  I've personally wasted a lot of time, and have seen others do the same, looking for solutions to a problem that was solved by new spark plugs.  Your list says that the plugs were already dirty when you put RCB's ECU in.  

The ignition module is weaker than later models but still, it's as good as points.  A tuneup, with new plugs, should get you back to baseline.  An improved ignition system will get you more time between tuneups.

Get back to baseline before swapping the big money stuff.  Seriously, I really have spent a lot of time on a problem, then put new plugs in and it went away. (I felt like an idiot.  No offense).

3 hours ago, Chickenman said:

you should be able to use your old 280Z cap and rotor if they are in good condition

The cap and rotor are different. I did the swap in my 77.

A good tune-up, as mentioned above, is a good start. I do a tune-up on my 77 twice a year. Over kill? Maybe, maybe not. It doesn't give me any trouble. Sometimes I think it's due to boredom. I adjust my valves twice a year and probably only put about 5,000 miles at the most.

Lets see a pic of the plugs also if you can. Are they all the same, sooty?

new plugs see if it drives ok, then pull them after a short while to read.

4 hours ago, rcb280z said:

A good tune-up, as mentioned above, is a good start. I do a tune-up on my 77 twice a year. Over kill? Maybe, maybe not. It doesn't give me any trouble. Sometimes I think it's due to boredom. I adjust my valves twice a year and probably only put about 5,000 miles at the most.

Lets see a pic of the plugs also if you can. Are they all the same, sooty?

I thank everyone for their good suggestions.    I'm planning to check out the simplest and least expensive offers first.  Alas, everything will have to wait until  2/3  when my social security arrives.  I will get the spark plugs first and check what improvement is shown then.  For sure I will share that information.  

To photo the current plugs, that will have to wait until Sunday or Monday when my son gets back in town.  We share a spark plug size tool.  

Thanks again to all, I knew I could count on your help with this.  You have never let me down!    

Jan     

Oh no,

RedBird says she won't go

No mo.

So here we sit

Having a fit

On the side of the road

Hope we don't get hit

Before towing get

Here.

 

Well... the good news is that an intermittent problem has now become permanent. That's easier to diagnose....  Be Safe. 

Well my friends...

We made it home safely.  Managed to not be struck by a idiot on the phone while driving.

Now this really opens up a mess for me.  RB is now driving exactly like before the old/new to her, ECU.  Going to store after Dr in Dalton, she refused to stay running.  The last half mile she was coasting, with me restarting her about every 3 seconds, to keep forward motion.   I knew then she would not make it home.  When restarted, she would chug and carry on like she was not running on all cylinders.  Very rough.  I did not want to press her on, I was afraid she might harm something else.

Here is a photo of our journey home.

Jai

Edited January 20, 20178 yr by Redwing

Since its the easiest thing to do, just unplug the ECU 35 pin and then plug it back in. Key off of course. Never unplug with the power on.

Edited January 20, 20178 yr by Dave WM

Just now, Dave WM said:

Since its the easiest thing to do, just unplug the ECU 35 pin and then plug it back in.

Is that on the inside of the cover, or outside?

Thanks...

It's under the plastic kick panel.  The screws are hard to get to.  The pedal in this picture is the clutch pedal.  I circled the connector.

By the way Jai, if you do any of the testing with the any of the coil wires or ignition be very careful. A leather or rubber glove is recommended they carry a lot of voltage and can be hazardous