1977 280z Fuel Issue

[Milenko2121]

I have been driving my car for the past month just fine, getting roughly 18mpg with no problems; however, I went to the store, and when I came back, my car wouldn't start.

I have a half tank of gas in the car.

I took off the boot between the air filter and held the flap open, and still no fuel being delivered(I also don't hear the injectors spray).

The flap in the AFM isn't opening when I give it throttle while turning over, is this normal?

I took off the fuel line before the filter and when I turned it over, no fuel would pump through.

I purchased a new fuel pump, but I have not installed it yet. I wanted to get some help as to what else I should check before I replace it and not waste money.

What else should I check before I just start replacing parts? And how would my car randomly just stop working like it did when it's been running fine?

Thanks for any help you can provide.

Edited December 16, 2011 by Milenko2121
typo

[Willoughby Z]

Welcome to the forums.

First, download the FSM (factory service manual) and the FI "bible". They're free and absolutely mandatory with Z ownership.

The flap, or vane, in the AFM- not FSM (see above) moves/ opens when engine rotation causes vacuum or draft which moves a metal rod attached to the vane shaft against one of the contacts of the fuel pump switch. With the key in the "on" position and the switch open, the fuel pump relay is energized, switching the pump on. The vane is not controlled by the throttle/pedal, per se. It is controlled by the vacuum created by engine rotation, as I stated before. There is a black plastic cover on the coil side that can be carefully pried off (usually held by caulk, sealer, glue... depending who's been in there before). Atlantic Z has an awesome write-up on the operation and adjustment/ calibration of the AFM. With pictures and captions and everything!

It could be that switch or a fuel pump relay (passenger foot well). You're right in that you don't want to throw part$ at a problem. Get the "books"...

Edited December 16, 2011 by Willoughby Z

[Inthenameofweez]

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.

[cozye]

Fuel should be pumping with the key in start position. Could be many things, I'd go through the troubleshooting section in the fsm. Could be something as simple as a relay. I wouldn't install the fuel pump yet, you may end up taking it back

[Willoughby Z]

A link for FSM

http://www.xenons30.com/reference.html

[Milenko2121]

Just got the fuel injection bible, It's late now, I'll run through those basic steps tomorrow. Hopefully I can find the problem.

It's just so weird that it ran just fine since I bought it a month ago, and when I turn it off, and then back on literally 5 minutes later, It no longer works.

[Willoughby Z]

Not so weird if you view it from the perspective that the car, and likely it's components, are 34 years old with 1000's of operation cycles. Think of how many times the fuel injector solenoids have fired...

Electronics of that era are a funny (or not so funny) thing some times.

[Milenko2121]

Not so weird if you view it from the perspective that the car, and likely it's components, are 34 years old with 1000's of operation cycles. Think of how many times the fuel injector solenoids have fired...

Electronics of that era are a funny (or not so funny) thing some times.

yeah, that's true.

thanks for all of your help, and I'm gonna continue this in the morning. I'll post with updates.

[240260280z]

What month is you 77? I think they switched from afm to fuel pump switch in May of 77 . After that it would be the oil pressure switch controlling fuel pump

[Milenko2121]

mine was built in febuary does anylne have a photo of the fuel pump relay? i cant find it under the mess of wires on the passenger dash

[Milenko2121]

i hooked up a 12v to my pump and the car ran fine

i just cant fknd my relay to test it... kinda rediculous now

[DonaldTrumpshair]

I think my ribbon relays for the fuel pump and injectors are under my steering column by the ignition stuff, I know the most common issues I have when mine won't start is either the fusible link is loose or those relays.