SteveJ

That would indicate you're guessing wrong. If the resistor was removed from the tach circuit, there would probably be issues.

Yellow and black = Fuel sending unit. Green = fuel pump power.

Is the resistor still in the circuit? Measure from the wire at the tach to the coil negative. It should be about 2.2K Ohm.

I took the 240Z out for Caffeine and Chrome this morning. The original plan was to drive the 260Z, but it was having an issue this morning that seems to be fuel related. I almost got rear-ended by a woman who didn't believe in proper following distances, but that was the end of the drama for a while. The great thing is that the heat took a break this morning. After a while, I had a nice chat with a gentleman who recently purchased a 70 from BaT. I provided him quite a bit of Z Car info.

I thought it didn't exist, but I just searched. It exists! This allows schrader valve replacement without losing charge. https://www.amazon.com/MASTERCOOL-81490-R134a-Remover-Installer/dp/B000KITSMI Of course, this is for 134A service ports. I'm not sure if one exists for R12.

That is jute. I didn't use any when I put in new foam and recovered the seats. I have the foam sitting in contact with the seat bottom.

Hanging out with John Morton today at Atlanta Motorsports Park. It was his first time on a track since his health scare a couple of years ago.

Interesting reading on the subject: https://ratsun.net/topic/67533-vacuum-problem/

I would think that with the improper function of the vacuum delay valve, you may not get the full effect of the EGR. The EGR helps to control NOx emissions by injecting some exhaust gasses into the intake to reduce the cylinder temperatures. In addition to the visual inspection, there is tailpipe monitoring. The test will look at hydrocarbon (HC), carbon monoxide (CO), and NOx. Typically HC is from the timing not being right or improper valve lash. You might want to read up on setting the valve lash to make sure it is correct. Heck, the correct valve lash will also give better performance. CO is from being rich. NOx tends to come from being lean or hot. Read through the EC section of the FSM and test/repair what you can. Make sure you have fresh oil and a full tank of gas when you test. Check your vacuum lines, especially for the carbon cannister. And as I said before, if you're in doubt, get a pre-test. If it doesn't pass, post the results if you need some guidance on repairs. As for the 76 year of manufacture, check the build date on the plate in the door jamb. If it's missing or illegible, check your VIN against the VIN range for 77. It could be that it was an 8/76 or 9/76 build. There are 3 years (sometimes 4) associated with a car: model year (sometimes the title may have a different year if a car was sold after its current model year), safety year, and emissions year. You would have to do some research to find out if the model year and emissions year differed in that timeframe.

They do test EGR functionality according to what I read, though I didn't find the procedure in my quick search. The part numbers are very similar. I cannot speak to functionality. When in doubt about your California smog test, ALWAYS get a pre-test. You don't want the car labelled as a gross polluter.

While no engine swaps happened at the last car meet, I did work on a friend's 280Z. He said he had to use his horn recently, and as he laid on the horn button, the horns quit. After a quick glance at the fuse box cover, I told him to step on the brakes. No brake lights - therefore blown fuse. Another friend had a spare 15A fuse. We went about checking other circuits. He had no side markers, either. That will have to wait for another day.

No problems so far.

Have you checked to see if the 280Z part is still available? I checked. It's not. Also, you can get that part from a dealer in the US if the 280Z part is NLA. https://www.courtesyparts.com/oem-parts/nissan-valve-assembly-vacuum-delay-14958v6700

What valve on the 280Z are you referring to? Do you even know what a vacuum delay valve is for?

I used LED bulbs on the dash. It's a lot easier to replace the bulbs with the dash out, but if your arms are not thick or short, you can replace the bulbs with the dash installed.

I installed some Wesco Roadster seat belts in the 240Z yesterday. They replaced some other Wesco belts that anchored at 3 points. I installed those probably 17 or 18 years ago. With the new belts in place, it was time to go to a car meet. Overall, about 9 or 10 Z cars showed up, but they were scattered about the meet. It was beautiful weather and a great way to spend a Sunday morning.

I should also add that if your horn relay is bad, don't expect to find a new 240Z horn relay. HOWEVER, horn relays tend to be pretty generic, and I believe this one would work, too: https://www.rockauto.com/en/moreinfo.php?pk=98819

It's at the top of the relay bracket.

Look at the junction between the engine harness and the dash harness in the passenger footwell. On the engine harness side, you should see 3 wires with individual terminals going to the horn relay. Those three wires should be green, green/red, and green/black. I'll see if I can snap a picture for you.

Dang. Time marches on. I see NGK lists this as a substitute: NGK 7133 BPR6ES-11 Nickel Spark Plug. I think I switched to those after seeing they were stock for the 280ZX. I have a ZX distributor in the 260Z. Rockauto lists the NGK 7131 for the 240Z and NGK 4922 for the 280Z. They also list Denso plugs.

You should be able to.

Here's my last photo of Dee from this morning. She loved looking out to see what was going on. She was a wonderful sentinel for the Amazon deliveries. It's been a tough day for the most part. Around noon I went to sit out on the front porch. Just before I went inside, I heard the raspy note of an old 4 cylinder as my neighbor took his MG out for a drive. I asked him how his drive went. He said there were no problems, and even the electric overdrive worked to his surprise. I told him that it was fed from the same relay we replaced. Anyway, he's the original owner of his 1980 MGB, and he takes pretty good care of the car. It shows you that a loving owner can overcome a lot of quality issues on a car.

That is the electronic fuel injection relay.

That merits looking at the connectors for corrosion.

No, it is not. If you want to test if the injector is getting the pulse to fire, use a noid light.