Bringing a 1977 Z back life

[EuroDat]

6 minutes ago, Av8ferg said:

On a side not.  I discovered I had some battery connection problems.  The two red wire coming from the fire wall were both connected to the positive terminal, looking at the cars wiring diagram one is supposed to go to negative and the other the positive. My battery positive side fuse link had on of the two wire cut,  I don’t know why there are two small wires from that connection but I connected one back to the positive.  Does this look right now?

 

They are not two wire on the fusable link. One is a clear plastic cord so the fusable link will not be stressed when pulled. Looking at the photo, someone cut the plastic cord off when they fitted a new battery terminal.

Second, I had trouble in the begining when I looked at the two wires going to the ECU. Both red doesn't make much sense. You would expecg yhe negative to be black, blue or something other than red.

[EuroDat]

Btw. The fusable link is still intact, although it looks like it is a little shorter. Looks like it has been cut and reconnected to the new battery terminal.

[Dave WM]

how did you determine which red wire from the harness went to which battery terminal?

[Av8ferg]

Dave, I referenced the 1977 wiring diagram in the attached photo.  It shows the one with a male connection off of the harness going to negative terminal and the one with the  female connection going to the positive.  Also the one with the fuse link apprears to be on the positive side.  I cannot connect it to the other because it would be male on male.....?

[Zed Head]

48 minutes ago, Av8ferg said:

I just pulled the power relay off..  Is there a way to test this off the car?  Here some close ups of it. 

There is.  Copied a snap from the 76 FSM, EF chapter.  There's another page of tests after that.

Looks pretty brown.  They run hot and can burn up after a while.

[Av8ferg]

Any votes here that I should buy a new Fuel Injection Power Relay?  They’re not cheap.  Can only find them on Z Car Source for $85

https://zcarsource.com/fuel-injection-relay-280z-75-77-new

 

[Av8ferg]

ZH, 

thanks Ill test it now. ?

[Zed Head]

You might have got lucky on your EFI power and ground.  But you should really check unknown wires with a meter before connecting them.  I like to check continuity directly at the thing that is supposed to be getting power.  Do this before you apply power and you'll know that you're not shorting directly to ground.

Didn't you already check power to the injectors though?  That's where that power goes, among other areas.

[Dave WM]

I would test using the diagram above it 1st see if you can figure out what's going on. that being said I guess a spare would not hurt, just remember to test it in the car once you get everything sorted.

[Zed Head]

I went back through the thread and it seems like, with the fuel pressure fixed, and the new connectors, and the big vacuum leak fixed, that you might be able to get a start if you can get power to and/or through your EFI relay, the one in your hand.  The relay you showed is actually the pump relay and the EFI relay combined.  Before getting too crazy with the testing you might identify which pin is a power wire from the diagram, then go to the plug under the dash and confirm that it has continuity to the battery positive.  Or, since you've already turned the key On, just turn the key On again and check for power there.  If you do have power, maybe plug the relay back in and check for power at the injectors.

Might be that the fusible link is burned and that's why you don't have fuel pump or injection.  You can check at the end of the fusible link also just to confirm, since it's attached to the battery.

Should have power at the red arrow if you disconnect there.  Although, sometimes the links don't burn completely through.  But attach a probe and bend the link around to see.

[Zed Head]

Actually, on testing at the EFI relay plug you could just probe all of the pins in the plug with the key On.  A couple or more should have power.  If none do then the relay would never work anyway.

[Av8ferg]

Okay, absorbing all the advice.  ZH, tested voltage to the battery fuse link and got 12.7v.  Fuel injection power relay tested good right out of the FSM.  The bad news is I cracked the board when crimping it back into the metal cover.  It’s still tests good but might need replacing now that I have compromised it.  

I’m going to find the power wire and see if Inget continuity now.  While rummaging around looking for wiring problems I found this on the passenger side above the fuse box.  Are these two barrel connecteors supposed to be connected to something?  

Finally can I test power to the injector plugs themselves.  I’ve read I should be getting 12v on them, but I’m getting nothing.  Disconnected the starter had my assistant turn key to the start position and then tested the  voltage from one pin of the injector connector and other to a ground.  Nothing....