Fuel injector Prob. 77 280z

[sideshowbob]

I really haven't the time to go through the whole post, but you've checked the fuel pump inlet screen, right? http://www.atlanticz.ca/zclub/techtips/fuelpump/index.html

(Also- how to quiet the pump)

[jagnew3]

I just got done checking...noone put the filter back. The car is only running 30-34 psi and it goes down below 30 when the throttle is @ around 2500

[jagnew3]

looks like a new pump...

[sblake01]

Don't trash that fuel pump just yet. Check your fuel pressure regulator as per the FSM as well as the fuel damper. A bad fuel damper can cause that fluctuation and a bad fuel pump regulator can cause that low reading. It should be a steady 36.3 psi. If you have a 78 FSM, check out page EF-37.

[jagnew3]

Well it all checked out sept the pressure..I decided to "rebuild" the pump now I got no psi at all...but it runs with a nice sound the mount was very loose, and now it's snug..but no psi ...at all Tank is full to the neck and either it won't prime, or is is done.....I wept..

[jagnew3]

btw..Bob..nice work there bro, sorry I didn't acknowlage the post's greatness sooner..again..very nice. Thanks

[sideshowbob]

That wasn't me, btw. That's the atlantic Z club's site.

Don't give up just yet. The pump will probably have to go, but you can still try to get it to prime. Heck, leave the car out on a hot day and the pressure in the tank will prime it for you.

1 - Get a spare fuel filler cap and insert a fitting for an air compressor or Inject fuel into the pump through the inlet line using a big syringe (being a bit nuts I would do this while the pump was running, just to check it out) then reattach the hose to the tank.

2 - Stick the AFM's air flap open to enable the pump

3 - Turn on the ignition (Don't crank)

4 - Pump should run for a while (2-3 minutes) then remove the AFM block

5 - Check pressure

You could also just tear the whole thing apart and try to see whats up with a PC power supply while sucking cleaner up through a hose and the outlet in an empty container or some such..... nevermind. Just try not to blow up, ok?

[sblake01]

The pump was working. You should have checked the other two things I mentioned before messing with it. Sorry but I only say that because I once replaced the pump on my Z only to find out that the real problem was the pressure regulator. As far as priming, well those pumps are self-priming so there has to be some other issue inside the pump or the check valve.

[jagnew3]

Oh I aint done yet.. I tried real hard all weekend not to get blown up..rog. I figured out that I put the inlet nozzle piece on wrong...so I redid that and thought for sure it would work...but no it still wouldn't prime..the thing is, there was a bit of fuel inside when I opened it up..how much does it take? There reall was not any at the out let, but plenty inside it seemed to me.

[jagnew3]

, I did check the regulator, and the dampner..prior to screwing up the pump. I didn't communicate that well when I said "it all checked out" sept the pressure. That's why I decided to take the pump apart..and sadly Iscrewed something up Sorry for the miscommunication.

[jagnew3]

The Check valve...inside the pump? something I notice when I had the outlet "barb" that has the check valve inside it, off was that the check valve didn't line up with the center hole on the outlet side of the barb..I tried to blow in..it sealed, and it opened up when I blew out.

[sblake01]

The Check valve...inside the pump? something I notice when I had the outlet "barb" that has the check valve inside it, off was that the check valve didn't line up with the center hole on the outlet side of the barb..I tried to blow in..it sealed, and it opened up when I blew out.

That is the check valve. You tested it and it's good. What you described is what it's supposed to do.