Inthenameofweez

I got a new ignition relay in there and no change. Brand new battery as well. Gauge lights work, engine cranks, and spark is there. I'm going to replace plugs and check compression just as a maintenance item. Noid light still not lighting on the individual injectors. Bu the cold start injector lights like a GD Christmas tree. And I know it's spraying fuel because I'll get a random fire from that fuel working its way into the cylinders... Help? I wanna drive this damn thing!

So, I found a common link between all of my issues. The ignition relay. Sure enough: So i tried to repair the ground with some solder of my own: I got the dash lights working. Brake indicator and tach are now working. Still no fuel indicator though. And no fuel injector pulse. I heard some shorting, and unfortunately I let the internal positive cables of the relay touch the negative body of the relay. And it burned the relay up. So I'm hoping that a new relay will solve all of these issue. Not sure what else could be causing no injector pulse. I just hope I don't have the same issues as this guy: http://forums.hybridz.org/index.php/topic/72897-280z-ignition-relay/ Until next year!!! That's all the wrote.

Here are some pictures of what I'm working with. There are 3 good fusible links. I have cleaned and verified that full continuity exists. The 4th one has been ghetto rigged because it obviously burned itself to death and melted the plastic case and wiring itself. I have questions about a few different issues.... Right now I have no dash lights, and no "BRAKE" or Battery light indicators. Before I started repairing things (main relay and fuel pump) I had blue/green dash lights and the previously mentioned indicators would light. Also, where does the lead from Pin 1 of the ECU connect to the ignition coil? I have verified that the fusible link controlling this wire is good, but I have not verified that the connection is good. I will include some pictures. Please give me a hint. Furthermore, there is a small blue capacitor looking unit next to the coil that had a wire disconnected from it. I have since soldered it back into place, but it changed nothing. What does this little cylinder do? And is it a replaceable part? Again, I'm really starting to suspect an issue with the ignition switch because I have no dash lights, the indicators no longer illuminate. Also, while testing at Pin 10 at the ECU, I only have 12V while in "ACC". I used a node light tonight and found voltage being sent to the cold start valve NO PROBLEM. However, there is no injector power. Zed Head, you mentioned a tachometer issue could cause no injector power. I am going to start reading the Body Electrical section, but in the mean time, could you expand on this issue? I'm am leaving the car for Christmas break (heading home) so I will not be able to work on it for a week. As I'm sure all of you will have family events during this next week, so I do not to hear a response for a while. However, even if you've got just a few thoughts, please share them. You can also see that the green fusible link seen in newer year Zs is not present on this car. This was manufactured in 2/77. Thank you again Datsun junkies and have a good holiday break from school and work.

I've got a node light. Gonna go play with it tonight. You're absolutely right. I pulled the cold start valve and it just cranks. I've also got a new battery. I'll be back online in a bit...

Omg. Everything makes sense now. I understand what you mean with the coil/cold start valve. So while I'm reading... what is your opinion as to why the injectors won't open? Bad/no signal from the coil? Edit: No. That can't be it. I've got 12V at pin 1...

I don't understand any of what you are saying. I'm not hunting an issue with the fire. I'm hunting an issue with the fuel. Ignition modules and lead wires make no sense as to why I can get it to run with starting fluid. And again, I have no green wires in my engine bay. I guess I needs to take a few shots of what I'm working with. http://www.youtube.com/watch?v=upVSDkadigg

Update: I can get a large amount of "sputter" while cranking. I am NO LONGER using starting fluid. There is some sort of a backfire in the intake manifold that is shooting a blue colored smoke out of the AFM. Not sure if I've got bad gas causing something or not. I'm going to get a 5 gallon gas can full of fresh 91 Octane and hope that I can clean out the junk in there. There are a few connectors inside of the engine bay that are creeping me out... I'll update in a few with more pictures and video of the "attempted" start.

Is what I'm holding referred to the Ignition Lead Wire? I have the FSM for my 77, but I don't see this green fusible link that is supposed to be clipped to the side of my relay cover. I will go check again. So if my tachometer is dead for some reason, I won't have injector pulse? As far as I can tell, while cranking, I have no tach reading...

Anybody have some ideas on what would cause the fuel pump to run normally and no fuel injector pulse? I am looking at the wiring schematic in the Bible and I see a few possibilities. I'm about to run out and start checking with a volt meter to see where my gap in power is, but what is more likely? Furthermore, where the heck is this damn fusible link? Is this in the engine bay? All engine bay links are OK and I still have no power to injectors. And this dumb ignition lead wire under the dash? WTF does it do? Haha.

No. A component issue more likely. Try playing with the flapper in the AFM.

Just because the relay clicks, does not mean that all circuits are operating properly. On page 137 of this manual: http://www.xenons30.com/files/FSM/77_datsun_280z.zip you will find the proper procedure for testing the power relay for correct continuity. You will need an Ohmmeter...

Yeah, I've checked pictures all over the internet, and my lines/rails are all hooked up right. I was listening with a screwdriver last night and heard no clicks. I'm wondering if the clicks are too quiet to be heard over the starter motor. Hoping to get plugs and node lights today. Any place that I can verify the proper order and placement of the spark plug wires other than the FSM?

Alright, so I've got a new fuel pump into the vehicle. Power relay is good. Sends fuel to the fuel rail like it's supposed to. It still won't start. It turns over like normal. It gets fuel. But either the fuel rail is clogged or the injectors are not opening. It is also possible that my plugs are simply so old and worn that all 6 have stopped firing. Or maybe the wires are mixed up. However, very unlikely, I will be replacing plugs and ensuring proper order of wires. In the mean time, I need to get some node lights to see why my injectors aren't opening...

We are having the exact same issues. I replaced my power relay (which I'm 150% sure is you issue) and I'm doing good. Still not running, but my pump runs in START like it's supposed to. The ACC instead of ON is a condition I also found. I'm pretty sure it's normal. Given that we're both having the same issue. The power relay is hidden right above the hood release. There are two large connectors plugged into it. Looks like this: http://www.atlanticz.ca/zclub/techtips/explodedviews/280z/77fsm/efi%20relay.gif

My parts car has a bad pump also. This one is shorted internally. (Sparks when touching each terminal). So I think I'm chasing more than one issue. I have a burned and replaced fusible link, a bad relay, and a weird response while turning the key to "ACC" and "ON". I'm wondering if any of those specialty Z shops in California have entire EFI harnesses laying around. I hope it doesn't come to that.... At least I have a parts car. Are the harnesses from 75 and (early) 77 the same? So given that I have the 12V signal going to the fuel pump while the key is "START", what can I confirm is good in this circuit? Simply the ignition switch, wiring, and relay? I may still have a bad ECU or one of the other inputs, correct? I don't even know if my dropping resistors or fuel injectors are okay. Ugh. I kinda just want to strip it all down and start rebuilding slowly after cleaning and verifying proper operation of each part/wire/component. .

Sooooooooo, I just checked for fuel pump action with a drill battery and nothing. Not even a squeak. So I've got a bad fuel pump for some reason. Hoping there isn't junk in the tank clogging it. So while I'm under there, I checked for the command under the "START" position. And guess what? I've got 12V heading to the fuel pump... This was all with the starting solenoid disconnected. I'm hoping that means that my previous worries about the ECU/RELAY/IGNITION SWITCH are false concerns. If I can get the pump to turn on during "START", then it should at least sputter and fire a bit, right? This 280 was built 2/77 and there is only 1 wire coming out of the pressure sender. I'm gonna go see if the pump on my parts car runs with voltage applied... BRB.

Yes!! Spark has been confirmed. I can get it to start with starting fluid. I tried to play with the AFM. How far do I need to push it up? I'll continue playing with it, but I'm not getting the 12V to the ECU (PIN 10) as the Bible tells me I should be. ("ON" position) Am I focusing on the wrong issue? Looking at the schematic, it seems that the Air Regulator could also prevent the pump from running. Do I read that wrong?

Any ideas on a way to bypass the circuitry to determine what wires might be okay and what wires might be effed? I'm gonna go power up the fuel pump with my 14.4V drill battery. If the pump proves okay, I can memorize the sound and confirm wiring/ECU. Again, the relay and ignition switch is okay. However, I'm still seeing conflicting voltages at the 35 pin connector. Pin 10 sees voltage in "ACC" and nothing in "ON" like it should...

I'm dealing with the same issues. Here is my thread: http://www.classiczcars.com/forums/showthread.php?44501-1977-FSM-not-helping. I recommend starting with the bible: http://www.4moores.com/280z/files/280zfuelinjectionbook.pdf Hopefully we have the same issue and we can work together.

So the ignition switch seems to be okay. Still have dash lights on "ACC" and no dash lights in "ON" position. Still have 12V in "ACC" and 0V in "ON" as monitored at pin 10 the large 35 pin ECU connector. All of the wires underneath of the dash leading from the ignition switch to the firewall seem to be okay. No obvious nicks or cuts that could be allowing the voltage to jump from one wire to the other. I just checked the fuel pump/main relay and all is OKAY according to the FSM.

Anything specific? Or simply corrosion or a loose wire? I'm going to check now. BRB. Yes. The Bible. I'm sorry. . My fault.

I'm currently diagnosing my 1977 280Z. In the "ACC" position, I have dash lights and a few relay clicks. In the "ON" position, I have no dash lights. no activity change. In the "START" position, the engine cranks over, but does not start. I've removed the fuel lines and I have no fuel pump actions during the starting position. No fuel pump action period... Here is a link to the manual that I'm currently using so that we can be on the same page: http://www.4moores.com/280z/files/280zfuelinjectionbook.pdf On page 33 it tells me if the relay clicks (which it does) that I should go to page 62, then page 61. So on page 62 and 61: I have full source voltage at pin 1 while in the "ON" position. While looking at pin 10, I only have .6 V. Now the funky part, is that I am testing the same two pins while in the "ACC" position and I see the numbers flip. Pin 10 is seeing the 12 V it is supposed to, and pin 1 only has 1 V. Is it possible that my ignition switch is messed up? I read the factory service manual as telling me that the fusible link is supposed to provide power through the fuel pump relay while in the "ON" position. I have replaced the fuel pump relay with a brand new OEM part from my Nissan dealer. This has not remedied the issue. Also, all fusible links appear to be in proper condition. (Confirmed using a Fluke Digital Multimeter.) All electrical parts are OEM as far as I know (other than an internally regulated alternator being installed). The previous owner let me know that his fuel pump died and he replaced it. 6 weeks later, it would not start one morning. I replaced the relay because it tested bad as per the FSM. The vehicle is currently sitting in my garage taking up space that my roommate could be using to park in (it's <30 degrees outside) so I'd really to fix this ASAP.

I'm currently living/attending school in Utah but I'm from Texas. Just bought a 1977 280Z that is complete. However, there is a fueling issue. I also own a 1975 that has no engine or trans. I'm extremely excited to get this 77 running so that I can swap the engine/trans into the much cleaner and rust free 75 chassis. Thank you for keeping this site up and running!!