"Airtex - Electric Fuel Pump
Part Number: E8312 "

Has anyone ever used that brand before? Is it any good form OEM replacement?

I'm almost sure my fuel pump is about dead as it takes awhile to build fuel pressure back up after shutting the car off. I'm sure that I'm also loosing fuel pressure through the pump as well.

 

Only true way to find out, is to hook up a pressure gauge from your fuel pump. Otherwise, I don't know that brand. What place are you getting it from? I would suggest doing a search on the brand of fuel pump. Good luck

 

put a fuel pressure gage on it and find out instead of guessing. possibly your fpr is shot. guessing and throwing parts at a car gets expensive. you can make this for under $20 and you will know what is going on.

 

I just changed the FPR with one that tested as good. And I cleaned up then tested my injectors, and their not leaking. So unless something else in the system is loosing pressure, it has to be the fuel pump. And I did use a Fuel pressure gauge. It was at 35-40 PSI at idle (if I remember right) but it dropped quickly after shutting the car off.

I haven't check it when the engine is hot. But if I drive then park if and let it sit for more then 5 min I have to let it build up pressure again. Which is noted by the fact that you can hear the fuel pump whining. It makes a high pitched whine when theres no pressure, then changes to a low pitched when when there is pressure. If I don't let it build up pressure the car obviously wont start.

 

So even though what you just said was pretty bad English, from what I gathered at the end is, it holds pressure while running but drops pressure after shut down. That would indicate that the valve in the fuel pump is bad and no longer closing to hold pressure after shut down. So in that case, yes, bad fuel pump, as for that brand fuel pump, I have know insight for you.

 

Sorry. I was half asleep when I typed that.

Well lest I was right about the pump. Guess I'll buy this one as its the cheapest fuel pump I've found.

Thanks

 

Okay. I pulled my old pump off, the screen had some junk in it but nothing out of the norm. But the check valve wont close itself without high enough back pressure. (AKA the spring doesn't close it). other then that the pump inside and out looks just fine. Replace it still?

 

Up to you. It does run fine correct? All that is there to do is to hold pressure once the pump and engine stop running so the car starts faster. More of a luxury than a necessity.

 

I ended up changing out the entire fuel pump. And its made the Z actually run MUCH better and idle much smoother. so maybe that old pump was on its last legs.

And other then being kinda loud, the fuel pump seems just fine.

 

Yeah, for some reason ALL after market fuel pumps are noisy on these cars. Though I'm sure a big factor in that is that it is an inline pump. Good to hear though. What was the fuel pressure at on the car at idle and when you revved it with the old pump? And was it noisy at all or sound to churn and not run at a complete constant speed almost as if it was surging? Those are usually pretty good indicators of something bad going on.

 

The pressure was around 35-40PSI and it was kinda stable if I remember. but it sounded like it was just churning the fuel instead of pumping it somewhat at times too (what I meant about the high low pitched sounds it made)

I did take the old pump apart tho. the little vanes didn't sit properly inside the pump, in fact they where very loose. So the pump was on its last legs anyways.

 

I put that pump on my z fairly recently but mine won't do the 3 second prime when you turn the key to the on position. It won't die out on me when I'm driving but it dies out still when I come to a stop or when I drive really slowly. I'm kinda iffy about the pump but I'm converting to triple carbs next year so I'm just gonna park it till then.

 

My Z has NEVER done the 3 or 5 second prime ever. And looking at the system. I dont think my Z was designed to anyways.

But so far this fuel pump is working great for me. my Z now just instantly starts up w/o waiting at all. Hot or cold. so I'm happy lol

 

It still takes mine a bit to start. It's not an instant thing. When i have a buddy turn the key to the on position when i'm under the car I hear it do a tiny, half second surge. It will show a couple volts with a multimeter too.

 

ALL fuel injected Z's have the 3 second prime! Where did you pull that statement from saying you don't think yours was designed with it?

 

From the fact that the fuel pump electronics have no timer in the circuit and its all relay based? Unless I missed a wire to the ECU or something. I'll check again.

And my fuel pump doesn't do anything at all till I turn the key.