Fuel pump and Relay problem

[Zed Head]

No continuity will make the engine run very rich once it starts. It tells the ECU that the engine is very cold and needs lots of extra gas.

Have you tried to start it again yet? If everything except the WTS is correct, it should start, run really rich for a little while then choke out and die in a cloud of blue smoke. If it won't start, check that the injectors are firing (although many cars will start on gas from the CSV, if it's working). The ECU grounds the injectors when it receives the "break" from the blue wire from the coil negative. Check for continuity between coil negative an Pin 1 with the key off. Or use a test light or test bulb to be sure the injectors are firing.

Edit - forgot one thing - the tachometer circuit with its resistor has to be hooked up for the ECU to work correctly. It's on the blue wire from the coil negative also. If your tach isn't connected the ECU won't fire the injectors.

Edited October 3, 2011 by Zed Head

[Brae]

i've tried starting it again, i cant seem to hear the fuel pump still, but the relay is clicking now, ill play around with the connection. it only starts with spray fluid still so i think my. theres a black wire and a green wire for the fuel pump, the green one is positive correct? Ill check the tach circuit make sure its connected then let you know if i find anything else. thanks for the help so far

[Brae]

Do you happen to have any pictures of the diagram or blue wire pictures

[Zed Head]

It's shown on the bigger diagram that you cut a section from in an earlier post. Blue is labeled "L". In the engine bay, the blue wire is attached to the big ceramic ballast resistor by the coil and disappears in to the wiring harness. IT basically "monitors" what's happening at the negative terminal of the coil. You can check continuity from there to the Pin 1 connector at the ECU.

Maybe you got your diagram from here - http://www.atlanticz.ca/zclub/techtips/wiringdiagrams/76_280z_wiring.pdf

You can see the connections on the lower left by the coil, distributor and spark plugs.

[Brae]

Ok the tach is working but no difference. I did however take a couple pictures of wires/areas I'm not entirely sure about and could really use some help with.

Edited October 4, 2011 by Brae

[Brae]

i noticed that for the 2 wires for the ignition coil and resistor in the middle, they are supposed to be dark blue/black but only one of mine is, the other is black/white

[Zed Head]

Now you're in to the fine details. The wiring diagram will help, and so will the FSM, and a multimeter or test light. I think that the black/white might be power to the coil positive. You can check by turning the key to On, it should have 12 volts. If you've already had the key to On and Start and didn't get any shorts, then you might as well turn the key to On and see what has power.

One of your pictures looked like the fuel pump wires, so it's not clear how you could hear the fuel pump running. You can test them for power also, by holding the AFM vane open, with the key On.

That's about all I have. Here's a link to a wiring diagram that's easier to use, from Saridout, a member of the forum - http://www.classiczcars.com/forums/showthread.php?36494-FREE-full-color-wiring-diagram-for-1976-280z&highlight=saridout+1976+wiring

[Brae]

The coil positive and negative are already hooked up but for some reason instead of having 2blue/black I have one blue/black and one thats black white.and I dont know the name of the part thats missing a connection by the bracket.the tiny cylinder shaped one

Edited October 4, 2011 by Brae

[Brae]

So I did a bunch of checks again then went back to the 34th pin to ground, for air regulator and fuel pump.did the check, no continuity.took out connector, checked air regulator, no continuity.i guess I need to buy a new one, that would probably cause my fuel pump not to be getting any power.but what I'm wondering is if that would also be the reason for injectors not firing

[Zed Head]

No power at 34 Don't necessarily mean no power at the fuel pump. Power to 34 is supplied though the fuel injection relay. The pump gets it's power from there also, but on its own line. You either have a messed up air regulator (AAR) or connection, not letting power through to Pin 34, which is only used to keep a fast idle for a short while, or no power from the EFI relay to the AAR, or no power to the EFI relay.

No power to the relay seems most likely, considering your other issues. The EFI relay is the 1x1x2" silver box up above the hood release knob. Check the wiring diagram and you'll see the circuits.

The AAR is an expensive item, and doesn't add much value. It's a convenience. You can check its operation by running 12 volts through it. It should close in a few minutes.

[Brae]

i put the volt meter on the green and black wire and the highest it ever went was like .04, is there a way to check just "88d"(one that goes to fuel pump) on the relay. When i put power to the AAR, it made no noise or anything and when i took the continuity of the 2 connector pieces, it made no noise or anything. if i hear my relay click twice(on and start), wouldnt that mean its getting power? I never got a close look at the wire but maybe the black and green wires just need to be replaced? maybe its heavily corroded, but im not sure how long the wire is and where it goes to after the fuel tank

[FastWoman]

The AAR won't make any noise. There's a heater inside it that will heat up a bimetal strip, which will slowly turn a damper to close the passage between the two tubes. Check the resistance between the two connectors. It should be about 65 Ohms, give or take. If it's ANYWHERE in that neighborhood, it's electrically good. That doesn't necessarily mean it's mechanically good. You'll know the mechanics are good if the engine starts with a higher idle and smoothly drops to a lower idle over a minute or so.