ectonine

the fuel pump went out in my 1986 rx-7 n/a, so i put the brand new fuel pump out of my 1987 turbo 2 car in the n/a. is this going to cause any problems? will it make it run rich or burn more fuel? also when i corner the car real hard to the left no matter how much fuel i have in the 13 gallon tank the car cuts out until the car levels out. is this the pump? does anyone else have this problem? how do i fix it--jeremie

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NZConvertible

Yes to both, resulting in less power. Get an NA pump.

ectonine

someone mentioned that no matter what fuel pump you have in there the fuel pressure regulator isn't going to let the car use more fuel. whats this?

hIGGI

iTrader: (7)

I am running TII pump in my NA car now and gas mileage or driveability is not affected by it at all. Old stock TII pump is not that strong to overrun FPR.

Kenteth

Works by ratio only. You don't set the regulator to Xpsi, you set it to Y%.

That said, if you got an aftermarket regulator or fuel comp, you'ld be fine...

NZConvertible

That is completely wrong. The FPR only alters fuel pressure relative to manifold pressure. It cannot compensate for changes in upstream fuel pressure. If you increase fuel pump pressure (and doing this will), you'll increase fuel rail pressure. Simple as that.

ectonine

damn nz! you're getting serious! i had to read your thread a couple times to understand hahaha. anyone got a stock n/a pump for me? my girlfriends from new zealand.

BlaCkPlaGUE

I would think that it only flows so much, even at the lowest pressure setting, it still cannot flow more than what the fuel pump can put out. Someone back me up on this.

Oh yea, I just got back from playing hockey ectonine and I feel fantastic!

Kenteth

I thought thats what i said?

ectonine

HAHAHAH! THE PLAQUE IS BACK!!! thanks for your help, and thanks for not blasting me about the damn search button. i'm honestly trying to read more and find things myself. its just hard being the new guy and everyone giving you ****. i apologize to you but icemark and i are gonna rumble--jeremie

NZConvertible

Whoa, serious misunderstanding! My reply was to your post "someone mentioned that no matter what fuel pump you have...", but while I was typing that hIGGI and Kenteth got in before me, so it looks like I was replying to Kenteth. Sorry if anyone got the wrong idea!

Having said that, Kentheth isn't right. The FRP doesn't work on a percent. It keeps the fuel pressure a fixed pressure above the manifold pressure (~37psi higher in our case), so that injector flow is constant.

Jodoolin

All the banter about pump differences has clouded a symptom ectonine has described "when i corner the car real hard to the left no matter how much fuel i have in the 13 gallon tank the car cuts out until the car levels out". That sure is a classic symptom of a dirty/clogged fuel pump sock. Maybe we should discuss that before he goes out and get a new pump?

Kenteth

Icemark eats noobs for lunch, don't mess with him.

Kenteth

I figured I was off a bit, but what I meant was that if its set at 37 psi line pressure at...say 40psi pump pressure, having 60 psi pump pressure will increase the line pressure at a constant ratio...

errmmm.. yeah.

Well thats what I meant anyhow. Made sense to me, but maybe I have the physics of the regulator confused, will it always hold the 37psi even if it has a changing pressure feeding it?

capn

is that what it is? because my 10th AE does the same thing on loaded high G cornering and i have been thinking its a grounding problem, where can i get s new sock then?

sub9lulu

iTrader: (7)

get a SAFC and tune it

Icemark

There is no such thing as a 13 gal tank.

There is only a 16.6 gal tank (86-88) or a 18.5 gal tank (89-92).

And the cutting out (as again covered in the FAQ for FC sticky thread- when will you start reading it???) is related to a dirty fuel pump sock. Replacing the pump with the wrong one will only make your fuel usage problems increase, while your power will decrease.

ectonine

thats what i thought about the 16.6 gallon tank but for ome reason my tank holds thirteen gallons, thirteen and a half if i really squeeze it in there.

ectonine

advance auto parts and autozone here in my town say the turbo fuel pump and the non turbo fuel pump are the same part. well they tell me the part number is the same for both--jeremie

Aaron Cake

iTrader: (1)

The Mazda parts are different. Your auto parts store probably just stocks a generic pump that fits all.

Icemark

If you completely drained the tank, it would take 16.6 gallons to fill it. You are probably filling it when the light is just starting to blink on.

No such thing as a 13.5 gallon tank in a RX-7.

ectonine

the light doesnt work in my car. i am filling it up when i run it completely out of gas and have to push it into the gas station. it only take 13.5 gallons at the very most everytime i fill it up--jeremie

NZConvertible

I see what you mean, and yes you're basically right.

Probably not. A bigger pump will probably result in a bigger pressure differential.

It is impossible to get the last bit of fuel out of any fuel tank, as the pump's intake is always raised slightly off the bottom. The fact is, an empty S4 fuel tank will take 16.6 gallons. Even though "it only takes 13.5 gallons at the very most every time i fill it up", there is still more than 13.5 gallons in there.

BTW, I really hope you don't let it run out of gas often (as you imply), as this will quickly kill the pump.

ectonine

two or three times to see what i am getting from top to bottom. one tank driving hard all the way through, one shifting at no more than 2,000 all the way through, and another half and half--jeremie

Alanrx7

Can you link me to a site where they sell the turbo ll fuel pump ?