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Fuel pump will not run. However, It will run when I jump across relay #25230. Please advise if there are other possible solutions to the problem. See picture of the relay. 20211011_171534.heic

20211011_171534.heic

20211011_171534.heic

20211011_171534.heic

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https://www.classiczcars.com/forums/topic/65943-fuel-pump-78280z/
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hey @James Que this message board has issues with `.heic` images. If I'm correct these are photos that are shot on a iPhone and might be uploaded from a Mac... You'll have to export the image as a `JPEG` so that other forum members can see the image on the website.

I've exported the image and attached it below.

20211011_171534.jpg

I'm not familiar with the safety features for a 280z, but isn't there a triggering circuit for that relay that is related to the oil pressure from the sender? There was a similar circuit added to a 260z to prevent the pump from running in the event of an accident.

 

I've also attached the export window in the `Preview` application if you are using `Mac OS`... if not please ignore, just know that the `.heic` images are not visible...

`Preview -> File -> Export -> JPEG`

 

Screen Shot 2021-10-18 at 9.19.13 AM.png

 

@Mike possible to have the  media service automatically convert `HEIC` to `JPEG`?

Edited by heyitsrama

Might be the fuel pump control relay.   Nissan doesn't list the relay numbers so it's not clear what relay  #25230 is.  Also not clear why you decided to jump some pns on it, you must have some knowledge of the system.

Another pump test you can try on a 78 is to remove the oil pressure sender wire from the sensor/switch.  When you turn the key on the pump should get power.  It will be a clue about at least one function of the system.

There's a ton in the FSM about testing the relay, if you want to get in to that.

image.png

image.png

3 hours ago, heyitsrama said:

hey @James Que this message board has issues with `.heic` images. If I'm correct these are photos that are shot on a iPhone and might be uploaded from a Mac... You'll have to export the image as a `JPEG` so that other forum members can see the image on the website.

I've exported the image and attached it below.

20211011_171534.jpg

I'm not familiar with the safety features for a 280z, but isn't there a triggering circuit for that relay that is related to the oil pressure from the sender? There was a similar circuit added to a 260z to prevent the pump from running in the event of an accident.

 

I've also attached the export window in the `Preview` application if you are using `Mac OS`... if not please ignore, just know that the `.heic` images are not visible...

`Preview -> File -> Export -> JPEG`

 

Screen Shot 2021-10-18 at 9.19.13 AM.png

 

@Mike possible to have the  media service automatically convert `HEIC` to `JPEG`?

@Mike. Thanks for you support with the pic and the option on the issue. 

  • 8 months later...

Just recently started back working on my 78 280. Got the fuel pump running. However, the engine will not start. Did complete the test of the engine electrical system according to the manuel, pages 30-40. All power sources check good based on the voltage and continuity test. In my trials, i have not had backfire or any reaction from the engine. Please advise of my next steps to start the engine.  Thanks, James Que. 

You have fuel, apparently, now you need spark and injection.  Have you checked for spark?  The distributors and ignition modules on these old cars tend to be bad.

Just do the old school way of sticking a spark plug in one of the plug wires and grounding it to the engine block while you crank the engine. 

Or squirt starter fluid in to one of the ports on the intake manifold then crank the engine.  If it starts but dies you'll know that you have spark, and can focus on injection.

It would help too, if you told people something about the car.  When did it last run?

I found it on your profile page.  You can put that info in your signature and it will show up in every post.  

"Zcars Owned

  • 280z
  • About my Cars
    My car is a 78' 280Z that has not ran since 2000. I purchased it from one of former student who knew my love for the car. SInce I am retiring this year, my first goal is to get it run with the engine that is in it."
     
    Here's a link to the Signature box.  It's in "Account Settings".  Don't know why.
     

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