1978 280z fuel pump not getting power

[Me280Z]

I just got a 1987 280z which is refusing to start.

 

When I got the car the previous owner thought that it had a bad fuel pump. I changed the pump but still nothing.I measured the voltage on the wires that go to the pump while turning the key and the wires get around 3 volts, but not continually. When the key is turned on it gets some power and then it stops.

 

I would really appreciate any suggestions of what I should look at.

 

Thanks in advance.

 

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[wheee!]

I believe the AFM needs to be active for the pump to run. It's a fuel shut off safety issue. No air flow, no fuel... The starting sequence allows a couple seconds of fuel to pump and start the engine, then air flow allows it to continue pumping.

[siteunseen]

His fusible link for the pump maybe about to burn in half, or need the terminals cleaned.

[SteveJ]

I could have sworn I posted how to bypass the relay TEMPORARILY. Maybe that was over at ZCar.com. Download the FSM (see my signature), and download a copy of the wiring diagram from Blue's tech tips. Since you're on a phone, you may have to go to a computer to see my signature. I don't know if the mobile apps show signatures.

In going back to look at that thread, it has enough to cover you for now.

Edited April 10, 2017 by SteveJ

[Me280Z]

I really appreciate you guys taking the time to respond. 

I am new to the Z cars, and this one I got is not on the best of shape. But I have high hopes that I will bring it back to life. 

Wheee - As far as the AFM goes, is there anything I can check if it is active or not?

Siteunseen - this is going to sound like a stupid question, but I am not sure which one is the fusible ling for the fuel pump is there a diagram which shows that.  

And lastly thanks Steve J for insight on how to bypass the fuel pump relay. I will try that and it hopefully will help me to narrow the problem down. 

thanks for the responses, and sorry if I am asking rookie questions.  

 

[SteveJ]

2 minutes ago, Me280Z said:

I really appreciate you guys taking the time to respond. 

I am new to the Z cars, and this one I got is not on the best of shape. But I have high hopes that I will bring it back to life. 

Wheee - As far as the AFM goes, is there anything I can check if it is active or not?

Siteunseen - this is going to sound like a stupid question, but I am not sure which one is the fusible ling for the fuel pump is there a diagram which shows that.  

And lastly thanks Steve J for insight on how to bypass the fuel pump relay. I will try that and it hopefully will help me to narrow the problem down. 

thanks for the responses, and sorry if I am asking rookie questions.  

 

To answer your question to Siteunseen, go back to my post and read it a little more slowly.  I say where to get a manual and a wiring diagram.

[Me280Z]

22 minutes ago, SteveJ said:

To answer your question to Siteunseen, go back to my post and read it a little more slowly.  I say where to get a manual and a wiring diagram.

I was not sure what you meant by your signature, I thought the things at the bottom for your comment were advertisement. This is very helpful, thank you.   

[wheee!]

The air flow meter has a black housing containing the electronics. If the butterfly doesn't move, no gas pump. You can artificially activate the pump by propping the butterfly open temporarily to see if that keeps the pump running. If not, it might have bad contact inside and need adjusting.

[siteunseen]

@240260280 has gotten a new image for his tech page. 

[El padrino]

Replace the fuel pump relay

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[El padrino]

Fuel pump relay

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[SteveJ]

6 hours ago, El padrino said:

Fuel pump relay

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Why throw parts at the problem before diagnosing it?