My new 280Z project -- advice, please

[Miles]

Note that "A" is next to the return outlet.

 

The answer is "A" because it is in the stream of water returning to the radiator from both sides of the engine. 

 

Also, it appears that you have already installed the temp sender in the correct location.

 

The oil pressure sensor installs next to the distributor.

Edited July 26, 2018 by Miles

[wingwalker]

Miles, thank you once again. That sender in the manifold was there, but not hooked to anything in the wiring harness--or what passed as wiring in this Z. The question is, will this sender work with the stock Z gauge, or should I, as the JTR manual suggests, buy their adapter and also buy a Z sender? Cheaper, of course, to just use what is there, but will readings be accurate enough? The oil pressure sending unit teamed with a cut-off for the fuel pump is also detailed in the JTR book, and I'll order the parts necessary to accomplish that.

 

This is all stuff I can get done in a cool room while awaiting temperatures that will allow me to tackle the many issues the chassis presents. However, next week my wife will be gone, so I may set the alarm lots earlier than she prefers and work in the main shop while it is still cool, then retreat when the temperatures soar mid-morning.

 

 

[Miles]

With the stock temperature gauge you have to use the original stock temp sensor with an adapter  that screws into the manifold.  If  you use a temp sensor from a different car, the temp gauge will not read correctly.  Same with the oil pressure sensor.

 

MSA and JTR both sell the temp sensor adapter.  MSA sells  the temp and oil pressure sensors.  So just buy everything from MSA. The plumbing  for the oil pressure sensor and safety switch is all 1/8 in. NPT you can get at the local hardware store.

 

My 240Z did not have a fuel pump relay, so I installed a Painless fuel pump relay kit and ran the safety switch to the trigger side of the relay.

 

On the 240Z there is an unused green fuel pump wire above the passenger kick panel.  The wire was intended for an electric fuel pump and terminates near the gas tank. Your 280Z may already be wired for an electric fuel pump. If not, Nissan may have also installed the green wire  in the 280Zs as well.

 

 

Note that the JTR manual is a little confusing on how to wire the oil pressure safety switch.  PM me if you have questions.

 

 

Edited July 26, 2018 by Miles

[wingwalker]

Miles, great information. I'll order those from MSA along with the engine/transmission mounting hardware. My wife leaves town in a few hours, and I have a credit card, so I'll do it while she's gone. (Actually, she's supportive of my auto addiction. Less trouble that some of the other varieties.)

 

I'm not ready to tackle the wiring mess yet, but when I do, I'll be asking about which wires can go away. I am okay reading schematics and wiring diagrams, but the one I have for this car is all on a single page--daunting. I go back and forth on this, and it may be a Painless kit, but if I don't go that route, I'll want to clean up the current mess, solder questionable spots and so forth, and then re-wrap it all neatly.

 

Thanks again for the help.

[Miles]

Suggest that you make a wire list such as in  the attached example. The wire list is for a 72 240Z. Confirm your 280Z wiring functions.

 

If you are unfamiliar with the ignition/starter wire functions, test each wire with a volt meter while turning the ignition switch to each position on the switch.

 

Note that the green-white wire was originally wired to the ballast resister on the 240Z.  Check if this applies to the 280Z. This wire provided direct 12v to the distributor when the starter activated. Attach this wire to the output side of the oil pressure safety switch to run the fuel pump during cranking.  This wire energizes at the beginning of the START position on the ignition switch and turns off when the key is released.  If you test it with a volt meter,  you will see that it energizes just before the starter begins to crank and de-energizes when the key is released to the  ignition position of the switch. This is useful to energize the fuel pump while cranking and to  fill the fill the fuel system when the car has sat for some time on carbed engines.

 

The diagram in the JTR manual (7th ed) incorrectly shows connecting a jumper wire (black-yellow) from the starter S terminal to the output side of the safety switch. Do not attach the  starter wire (black-yellow) to the OUTPUT side of the oil pressure safety switch. If you do, the starter will continue to crank once the oil pressure pressure safety switch closes. JTR warns of this in section 13-2 of the manual.

 

I tested the oil pressure safety switch before installing the engine.  It closes almost instantly when the oil pump starts turning.  No problems after nine years. To avoid burning/straining/overloading the switch wire the output to a fuel pump relay. No problems after nine years.

 

 

 

240z Wiring Tag Numbers Table.xls

Edited July 26, 2018 by Miles

[wingwalker]

Miles, again, thank you. This list is perfect. I'll test it against the 280Z wires and the schematic I have for it. This'll keep me out of trouble.

[Miles]

2 hours ago, wingwalker said:

Miles, again, thank you. This list is perfect. I'll test it against the 280Z wires and the schematic I have for it. This'll keep me out of trouble.

 

Note 280Z wire color for the oil pressure safety switch: http://forums.hybridz.org/topic/110528-jtr-bookwiring-issues/

 

Per JTR pg 13-2:

 

"If you are using the HEI  distributor, the easiest way to wire the fuel pump for cranking conditions is to connect the Green-White (240Z) or black-blue (260Z/280z) wire to the fuel pump wiring."

Edited July 27, 2018 by Miles

[wingwalker]

After I said goodbye to an earlier project, an Alfa Romeo Spider (photo below) that is on its way to a new owner in Everett, WA, I decided the brave the heat and go into the un-airconditioned portion of my shop to tackle the engine compartment.

 

I lasted a couple hours before I felt I was endangering my well-being. So I came in for, as my wife puts it, hydration. A beer would be wonderful, but I'm drilling out spot welds and that takes all my concentration (to keep the cutter from wandering all over the place). So the hydration comes from a mix of ice-tea and lemonade. I think it's called an Arnold Palmer.

 

On our back deck--which is covered and enjoys a nice breeze--the thermometer reads 101. I'm guessing the air in my shop, which is still and warmed further by radiating heat from the metal roof (no ceiling or insulation), is maybe 15 or 20 degrees above that. Hot, hot, hot.

 

Before I came inside I had cut out a number of extraneous brackets. I started in on the battery tray, which in several spots is tough to get the cutting tool to , so I when go back, that's the challenge I face. I am likely to be disappointed by serious rust under it, more than than what I see now.

 

While working there, I was pleased to find that the previous owner brought the brake line for the right front up to the top of the frame rail. His bends were a bit tidier than the illustration in the JTR manual. Nice.

 

I do have a question. I have searched this site and not found the full answer. There are three fuel lines coming from the rear of the car. I believe the smaller one is a vent line from the tank, and the other two feed fuel and then return what is not needed (as FI systems like to do). To clean up the engine compartment a little more, I am thinking of eliminating one of those lines. My engine will mount a carb--a new, still-in-the-box Holley 650 that came with the car, so I won't need the return. If that's a bad idea, please tell me. And could I vent the tank back in the rear and bring only a single line to the engine compartment? That would really tidy things up. Is that done?

 

Here's the engine compartment and a shot of my Alfa (also purchased non-running).

 

 

And while we are on this topic, why not bring the lines up on the firewall instead of leaving them along the frame rail near the heat of the header? Is that done?

Edited July 29, 2018 by wingwalker

[Miles]

I do have a question. I have searched this site and not found the full answer. There are three fuel lines coming from the rear of the car. I believe the smaller one is a vent line from the tank, and the other two feed fuel and then return what is not needed (as FI systems like to do). To clean up the engine compartment a little more, I am thinking of eliminating one of those lines. My engine will mount a carb--a new, still-in-the-box Holley 650 that came with the car, so I won't need the return. If that's a bad idea, please tell me. And could I vent the tank back in the rear and bring only a single line to the engine compartment? That would really tidy things up. Is that done?

 

For a carbed engine all you need is the fuel line.  Trace the  return and vent lines back to the gas tank and mark the tubes that they connect to.  Any tubes not used on the gas tank will have to be brazed or welded closed.

 

You can also eliminate the vent tank and all of the hose  connections to the gas tank. If you eliminate the vent tank, you will need to drill a 3/32" dia hole in the gas cap to vent the gas tank as it empties out.  There are several threads on this throughout the forum.

 

Keep at least one of the vent tubes on top of the tank bulge and run a  hose  to the gas filler hose nipple. This allows air to escape while filling the tank to the top of the bulge. 

 

Attached are pictures of my 240Z fuel Lines.  I haven't had any heat related problems, but I did run the fuel line the electrical harness through thermal  protective sleeves on the passenger side near the headers.

 

Since you will have to drop the tank to modify the various hose connections, you might as well install a new fuel gauge sending unit.

Edited July 30, 2018 by Miles

[wingwalker]

Miles, this is so helpful. Right down to the part numbers. Since my tank is already out, I'll perform those mods to it. And replacing the sender while it's out is solid advice. Just a single fuel line to the engine will make it all less complex. And cleaner.

 

Good tip on drilling the filler cap--I'd have gone nuts trouble-shooting that as the engine stalled a little while after starting it.

 

Your engine bay looks awesome in the partial photo you posted, by the way. I searched to see if you had written up either of your builds and didn't find it. Did you do a write-up on that second build? Or the first? I'd love to see it. Or at least a full shot of the engine compartment.

 

Thanks again for your help.