New to me, 280Z...

[dar5052]

Can someone help identify where these connectors go? The yellow wire goes into the thermal transmitter but I can't figure out the red, white, or black. For the white and black the manual says vacuum switch solenoid. I can't find it, maybe I'm missing parts. The red is supposed to go to a water temp switch, I can't find anything to connect it to. Photos would help. For reference, it's a 76 280z. The red circle in the Pic below is where the loom connects. 

[Yarb]

Does it have Nissan ECU or aftermarket?

[dar5052]

Stock ecu,  non cali... I should have taken more pics when I took it apart. Unfortunately the ones I have, I can't see this area 

Edited August 2, 2024 by dar5052

[Zed Head]

The vacuum switch might be for top gear timing advance.  It opens vacuum to the vacuum advance canister on the distributor in high gear.  Retarded ignition timing is cleaner than advanced.  It's an emissions thing, some people remove it. 

The water temp switch is also emissions related.  It switches to the more advanced timing pickup in the distributor when the engine gets warm.  If you don't have the dual pickup distributor it doesn't matter.  

I think that cars with catalytic converters might not have either of those,  CA vs Federal.  I had both.

Too many pages to go through and figure out what exactly your collection of parts is.  But you don't really need either of those things, by the labels you gave them.  Just make sure that any loose wire ends aren't powered and/or are protected.

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Edited August 2, 2024 by Zed Head
the usual

[dar5052]

@Zed Headthanks for the thorough explanation. 

[Zed Head]

A followup - The water temperature switch is in the thernostat housing.  There's a wire to an eyelet that is supposed to attach to a mounting screw for grunding.  The wire often breaks right at the junction with the switch body.

The vaccum solenoid would be mounted somewhere near the front of the engine above the intake runners of the first two cylinders.  Notice that the black wire is a separate wire with a bullet connector and an eyelet, to connect to a screw for ground.  Easy to lose, it's just a short little wire.

[Zed Head]

I think I found a picture

[dar5052]

Thanks @Zed Head. I remembered I had another head in storage so I went and looked at it and found the connectors there. 

 

I went to fire the car up today and couldn't get it going. It started a few times but ran rough and shut off. I have decent compression, oil pressure, and spark. I know that My fuel pump is kicking on when I hit the "start" position on the ignition. Oddly it doesn't prime in the "on" position. Is that normal? 

 

Baeed on some things i have done so far, seems to be a fuel delivery issue. I am troubleshooting with the EFI Bible and am wondering if anyone can point me to the ignition lead wire. See photo with highlighted sentence. Thanks in advance. 

[Captain Obvious]

11 hours ago, dar5052 said:

wondering if anyone can point me to the ignition lead wire.

That connection point is above your left knee. It connects the output from your ignition control module to the EFI harness.

If the car starts and runs at all, then that connection should be OK.

[dar5052]

I don't know if I would call it starting and running. If I hold the throttle all the way down, it will fire up but run very rough and die when I lay off the throttle. 

Would there be audible clicking from the injectors when trying to fire up? I had someone try and start it while I felt the injectors to see if I could feel them clicking open but I couldn't feel or hear anything. I checked the voltage for each injector at the 35 pin connector and each has 14V going to it. 

[Zed Head]

The fact that it starts implies that the wire back to the coil is correct as CO says.  The tachometer, ECU, and ignition module are all on the same circuit.

The fact that it runs best with the throttle wide open kind of implies that it might be super rich.  That could be from a hole in the fuel pressure regulator diaphragm or if the coolant temperature senosr circuit is open/high resistance.  You might do the Pin 13 resistance measuremnet at the ECU and see if it's in the right range.  And pull the vacuum hose to the FPR to look for fuel.  It should be dry.

p.s. you can test the injectors using a jumper wire from the coil negative terminal.  Attach a jumper, turn the ley on, and tap the wire quickly to ground repeatedly.  Every third tap should "click" all of the injectors.  Don't do too many "clicks", each one squirts fuel in to the intake system.  This will test the wiring and the ECU function.  It's pretty east and you don't have to listne over starter moise.

Of course, you can also use Noid lights in an injector connection too.  The factory way.

 

But, hopefully not the case, you migth also have a bad ECU.  They run rich as they start to die.

[Yarb]

Do you have a fuel pressure measurement reading after the fuel filter?