Ah, the lower energy ignition system...forgot about that. 

 

 

According to the FSM and the previous plugs: The gap should be 0.7 to 0.8mm (0.028 to0.031 in)

Thanks for the refresher Greg. For some reason I keep thinking 77 instead of 76.

She has a 76 with the lower energy ignition system.  You might be thinking of 78 and on.  Spec. for 76 is actually .031 - .035" so it was on the high end.

 

I looked back through the original thread but can't find anything about miles on the engine.  My 76 had high miles and worn valve seals and burned some oil at high RPM.  Those plugs seem pretty black and the fact the engine ran very well but you still ended up with black, wet plugs, after just a few miles with the new plugs seems to indicate some oil leakage in tot he cylinders.

 

I can't recall much at all either, about the general state of the car when received.  Maybe it's a high mile car that sat, or a low mile car that sat, or a high mile car that was a daily driver.  The first two could cause a little rust in the cylinders that might wear in to shape, the last would mean it just is the way it is.

 

Someone mentioned Italian tune-up a while ago, I think.  Maybe it just needs some good road runs to settle down.  The daily warm-ups and mail box trips though, might not be enough to keep it in good shape.  They like to run.  

A Nissan mechanic told me once that short trips are bad for these engines. Never get warm enough. These cars need to be driven.

Gwri8

Thanks for your effort. I think you're right about the gas. Hopefully RB is going to be reliable now. Is the potentiometer add-on the best method of leaning it out a bit? Temporarily, will keeping the revs up keep it clean enough to not foul plugs? In your opinion.

I have never used the potentiometer trick so I'm not sure, but Siteunseen, Fastwoman and others on the site have used it with success to compensate for aging ECU's.  What was referred to as a redneck tuneup or a Italian tuneup, sure, blowing out the carbon every once in a while won't hurt. 

The pot trick is for the lean drift issue the 78 has. Guess some 77's also have it. So it adds resistance which adds more fuel. Wont lean it out, according to the members using it.

sure looks like it's running rich + getting some oil

 

worn/dried-out valve guide seals will suck oil into the chambers during deceleration (vacuum conditions) causing a surprising amount of oil burn. they are cheap (less than $20 IIRC) and not tough to install. you get a free valve lash adjust out of the deal as well 

 

i've replaced a couple sets and the results have been noticeable. 

 

everything i've read says not to run an L6 below 2K revs as it will carbon up. i don't believe 4K is "pushing it" - that's a basic shift point. rev it up to 5K regularly, it's meant designed for it. just gotta re-calibrate the brain from old american iron...

Hi guys,

I happily am thanking you for all the recent information. Yep, I do remember with Redwing (my 240Z) the value of regular zooming to clear her lil head out. I drove on interstate about 30 miles round trip 5 days a week. That was when the speed was higher too. My feeling was that she didn't begin to run well until over 5000 RPM. Like a horse, she laid her ears back and eased into stride gracefully. She never had any of the carbon on her spark plugs. Right on!

I am interested in the valve guide seals, sounds like that might be a prudent application for her. I need to source them, are they a set, or $20 each? I am so thrilled that Greg replaced the plugs yesterday, our trial run was exhilarating. Of course, the work Steve and Tim did 10 days ago was the prime work. Greg's work was the nuts on top of the HOT FUDGE SUNDAE. Hehe... I will be driving tomorrow and Friday. Will remember, for the both of us, to Zoom some.

I took a photo of Greg and his beautiful Green Mistress yesterday, and he ok'd me to post it for you all to see. Natch, this is only a cell phone photo. Greg will post a Real photo eventually. I just wanted to brag on her tho.

She is very beautiful.

Aghhh, battery almost dead, will edit and add later. Promise!

Jai 😇 🚘

Edited November 4, 20159 yr by Redwing

Today was a very eventful day for RedBird. She drove wonderfully to Advance Auto. I did manage to get the alcohol fuel treatment, but she would not start when leaving. Starter fluid into the manifold had no effect. So we sat. Eventually she decided she had taken enough of my time, and started. I bought 3 gallons of gas, and we drove around a bit to mix the treatment in with the gas. Revving her as often as I could to keep those RPM's up. Went to the vet, parked away from the other cars like I always do. THEN someone who did not look at all, backed her van into RB. Cops called, information shared, thank God she is insured.

It is not horrible, but anything hurts. I really almost lost it, makes me sad. After everything, now this.

Jai 😇 🚘

What a sad thing to happen just as things were coming together for you and your car.  Makes me sick.

 

Have followed your thread for a while now,and just wanted to say I wish you the very best of luck Jai with the outcome.

(at least the door does not appear to have any damage)

I'm sorry your car got hit, Jai. Vans do not like Z cars. My 240Z was hit by a van 18 years ago. My car was parked at a gas pump and the driver cut the corner too much.

What a tragedy!

sorry to see that - let's hope the insurance takes care of you.

If people will just pay attention to where they are going. And then there are the ones that drive drunk and completely destroy your car. My 260 was totaled when a drunk driver slammed into her while parked in front of my house. Had just put down a 2 part epoxy on the garage floor and it had to dry for several hours before I could park on it. But, if it wasn't for the 260 the truck would have crashed into the house. We only lived there for about a year after that. Didn't feel safe anymore. They said the drunk driver was traveling around 50 mph!