Av8ferg

ZH, with the ignition “ON” I get 12V on pins 70, 71 and 73,

Tested both plugs that go to the Fuel Injection Power Relay. Only one showed voltage and that was pin 70 which goes to the positive battery terminal thrrough the fuse link on the positive terminal. I got 12.7v. No voltage on any other pin in the plugs. Where are the dropping regsistors located?

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....

ZH, thanks Ill test it now. ?

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

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.....?

On a side note. I discovered I had some battery connection problems. The two red wires 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 one of the two wires 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?

ZH, thanks. I found that hose to the canister. I just pulled the power relay off.. Is there a way to test this off the car? Here some close ups of it.

Gents, back working on the Z. I’ve solved a couple problems but still have others I’m working on. I’ve got fuel pressure issue fixed. It’s holding stable at 35-40 psi with the pump running. I still have to jump the pump to the battery as it will not work with the key. I disconnected the starter power and stated going through the checks in the FSM. It appears I’m getting no power to both the fuel pump or the injectors. I also don’t hear any click on the drivers side kick panel. Finally, I have need help with something on the intake manifold. There is small connection that I don’t know where it is supposed to go. See photo. When I try and start the car it spits air out this hole. When I putting starting fluid in there my assistant said a blue flame shot out of this hole. Any ideas what’s supposed to be attached here? Sent from my iPhone using Tapatalk

Zed Head, Thanks. That might have been the problem. I don’t think the key was in “On” I think it was in “ACC”. I hope that was the bonehead mistake I made. The old ignition switch was definitely bad. Tested both new and old side by side with the multi meter. I’m on a work trip will attach when I get back. Thanks for the link. [emoji106]. OBTW I meant crank not turn over. Words have meanings especially when details matter. Sent from my iPhone using Tapatalk

One humiliation after another. Got the switch installed and when i turned it over got the “floor heat” (not sure what the heck that light means), no other lights (oil pressure or brake). I stated to go through the steps for No Start in the EFI manual. During the power relay test I didnt get a click sound from relay, I tested yhe voltage at it stated on pin 4 and a ground and got nothing. Says to go to service manual EF-47. I cannot ge the FSM on my ipad (wont unzip and asks for password, downloaded from Xenoncar) and dont have a laptop with me. I’ll print the FSM at work tonight. This is getting painful. As soon as I think I might have found a solution I hit another roadblock.

Good news. Just tested my ignition switch and it is totally dead doing the continuity test. I just bought a new one, tested it with the multimeter and now headed to my garage to install it. Will report back.

Dave, I saw a guy posted a video of testing his Z ignition switch. You’re right it looks fairly easy. I’m glad a replacement is affordable if it is bad. When you don’t know the history of a vehicle and why it came off the road 18 yrs ago so many things can be wrong.

Cliff, When I got the car it had no battery. After putting in a new battery in and trying to turn the car over, I got nothing, no powerto anything. I check the normal fuses in the passenger kick panel and they were all good. I then jumped the stater terminals with a screw driver and I could get the engine to turn over. This was how I did my engine compression check. I did some research and I read about the fusible links in the engine compartment and how they could be a problem. My car was missing one fusible link and the other two looked old and cracked. I bought all new ones and cleaned the terminals well. That enabled the car to turn over. I still have no interior lights. I’ve never tried the turn on the headlights. Is it possible I have a bad ignition switch? Could that also explain why the fuel pump doesn’t work with the key in the “on” position. I don’t want to jump to conclusions here.

Thanks for the link to the EFI Theory and Troubleshooting guide. Ive been reading it from begining to end,. I learned a lot and its given me a logical path forward. I head back to Memphis to work on the car this weekend. First step in the troubleshooting section says that the greatest source of problems with the injection system is the connections. Like I said before mine are in terrible shape. While I know Zed Head mentioned that i need to focus on isolating the probelm step by step, I feel not addressing the wiring/connections will lead me down some rabbit holes. i.e. thinking i have a bad component vs a bad connection. Also, something I have forgotten to mention until researching starting issues online that I wanted to ask you pros if you think it could be another clue to my issue. When I turn the ignition key to the “on” position I get no lights in the car. I mean no dash lights. I think I'm suppsed to see the red “brake” light and the red oil pressure light and possibly a buzzer. I could be wrong, I dont know what I'm suppsed to see becasue i see not lights at all. Thanks.

I do appreciate the help in case I forgot to mention it. I’d be way behind without your help. Sent from my iPhone using Tapatalk

BTW, I’m laughing because my wife always says I need to focus on a single task too. I’m distracted easily [emoji849] I think part of it stems from the work I do. I flew fighters for 21 years and you are constantly changing tasks.

Zed Head, Agreed, I don’t think the connectors are the reason it’s not starting but I do know mine are bad. They are cracked and will not stay on the injectors. They pull off with not effort and will not lock in. They need to be replaced. Since I’m running through the FSM continuity checks and already found a problem it’s seems prudent to make sure the connections are solid. I don’t think it’s too outside the box. I know I need to test the AFM, I know the tank is shot and I plan on addressing those items as soon as I return. Sent from my iPhone using Tapatalk

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I went ahead and pulled the trigger on a set on eBay from Classic Imports 240z seller. He’s got great reviews and seems to deal on classic Z parts. https://m.ebay.com/itm/Fuel-Injector-AFM-TPS-Wiring-Harness-Connector-Kit-for-Datsun-280z-Nissan-280zx/152245949681?fits=Model%3A280Z&hash=item237290d4f1:g:MwsAAOSwhQhY2B2G Sent from my iPhone using Tapatalk

Let me know if you find them. I see all sort of variations on eBay. Prices are wildly different. I want to order them tonight so I can bring them back to Memphistan. Sent from my iPhone using Tapatalk

Here’s a photo I took before removing the fuel rail. I can see what your are talking about. Sent from my iPhone using Tapatalk

EuroDat, Great explanation, I will check that as soon as I get back. I checked my other photos and I just can’t see under that hose covering that connection. One note was after I had all that pressure when I tested the rail I could later hear gurgling back near the fuel tank. It sounded like fuel slowing returning to the tank. This was several minutes later. I’d think it would have occurred almost immediately. Might be indicative of a small blockage in three. Sent from my iPhone using Tapatalk

Well, I was just asking if electronic ignition is a good way to go. You are correct, I haven’t tested it yet but up to this point just about everything seems to be bad on this car. It sat for 18 yrs in a garage. To be honest I haven’t even researched how to test my distributor. I have tested the coil and it’s firing. Last time I sprayed starting fluid in the intake and turned it over I got a small pop and fire started at the entrance of the intake manifold. Sent from my iPhone using Tapatalk

Zed Head, You’re not being an arse. I appreciate your candor. Sent from my iPhone using Tapatalk