1) Can I run 4 x 720cc injectors with a 255lph pump and stock fuel pressure regulator? Temporarily for startup/ troubleshooting?

2) Is there any need to upgrade the stock feed or return lines in the fuel sending unit if I am planning on using above fuel system and looking to run about 300hp max??

I am considering installing all new SS fuel lines from pump to filter to injectors to aftermarket fpr back to the tank, although I don't think stock looks to be in that bad of condition.

3)Maybe I should just install the aeromotive fpr inline with the stock system??? At least then I could remove the pulsation dampener right??

Thanks so much for all of your help with this matter, I really do appreciate all the good advice I have recieved so far, it would be a lot harder without you guys...



Thanks alot.

 

Yes you can run 4x 720cc but why? Also you need some sort of fuel managment system to handle the larger injectors. Also Yes you can replace the Pd with a Banjo bolt, or replace the whole fuel system with ss lines an -an fittings.

Also for running up to 300hp you might want to consider getting your turbo ported and new exhaust, less restrictive tid and maybe a fmic.

 

let me clear this up:

I have 720cc fuel injectors installed as both primaries and secondaries.
I have an aftermarket fuel pump that flows 255 liters per hour installed in tank.
I have an Rtek7 Stage 2.0 ECU to manage fuel delivery installed.

What I was trying to ask is should I run :

A) Stock fuel lines(including the stock sending unit) and stock fuel pressure regulator since their in decent condition.

B) Stock fuel lines with Aeromotive Fuel Pressure Regulator

C) All new SS lines with -AN fittings with Aeromotive Fuel Pressure Regulator


Also, I didn't feel the need to elaborate and give my whole spiel but, since you asked:

The turbo is going out to BNR next week to be rebuilt, upgraded to Stage 1, balanced, blueprinted and the wastegate ported to 30mm.

My current exhaust is wide open - racing beat downpipe from turbo to straight 3" exhaust out duals - no cats or restrictions-

I am fabricating a cold air TID utilizing the stock AFM as we speak.

The intercooler will be upgraded to a GReddy FMIC within one month and will be installed before any boost over 10psi.

Basically - do i NEED the aftermarket FPR right away to run my 720's?? Thanks.

 

No you dont need a FPR for 720s, you should be find. If i can remember clearly you can run up to 350hp wit a stock fpr/fuel system except the fuel pump part.

 

thanks, anyone else able to confirm that??


but how bout this:

i just (this afternoon) installed the (4) 720s along with the fuel pump supplied by Venom put it all back together and now the car won't start. It rotates but doesn't fire up. It was just running before I swapped pump and injectors. The fuel pump is pushing fuel but the exhaust doesn't reek of gas like when it's flooded, it seems like it isn't reaching the injectors.

Do only the primaries spit fuel when cranking? I haven't a clue, the EGI fuse is good also...Injectors had proper resistance before installation. Thanks

What could be going on????

 

did you use high impendence injectors or low impendence with resistors inline?

 

they measured 2-3 ohms i recall, they;re low impedence injectors anyway, just like the old ones.

So if i pull of the reurn line at the tank and crank the engine fuel should pour out of return indicating that at least fuel was reaching the rails correct, i'm gonna try this tomarrow morning.

Any ideas are welcome.

 

when you put in the new pump, did you get the return and supply hose mixed up on top?

 

i am pretty sure that they are correct, the hard lines are staggered aliitle, like onebehind the other a little and the fuel ines were cut to match, so they went on just as they appeared to go. if installed backwards there wuldn't be fuel coming back to the tank right, it would stop at the pressure regulator or the filter??

Im gonna look and see if fuel is returning to the tank.

While we're at it, is anyone else able to confirm that i can run those 720's and the aftermarket pump with the stock FPR??

 

bump bump - where are the fuel guys, i read faqs, i need real life verification on fuel upgrades, who has done this before?

I'm leaning toards just installing a new frp along with all new rubber fuel lines from tank to filter to injectors through new -an fitting to new FPR back to tank.

please lend your experience, i have never upgraded fuel systems before. Thanks again.

 

^if you plan to go bigger later why not just do the aftermarket FPR and run it in a parallel setup. http://fc3spro.com/TECH/MODS/FUEL/fsystem.htm ive done this on my old na and my turbo car and its worth it.

 

ok. This is thing with that parallel setup, if my physic class serves me right, that set up will result in uneven pressure between the rails, something like p1v1 = p2v2 or something, basically since the I.D. of the lines is the same but there will be a longer run in one line there will be a lower pressure due to the great volum in line. Fluids travel the path of least resistance and I'm afraif this might affect fuel fuel in a negfative manner, I am wondering why mazda designed it the way they did if it could have been done differently, I bet they considered it at least once and decided to go with the series setup.

I will retain the series layout when I upgrade no doubt that is what I have decided. Instead of using all SS ines I will be using something similar to EARL'sb Super Stock Hose and Auto-Fit -AN fittings to replace the entire fuel system. I will retain the stock feed and return from the fuel tank, but I will be eliminating the pulsation dampener and replacing the stock pressure regulator with an Aeromtove unit.

 

Just to close this, I fixed the car, well it starts anyways and runs like it used to. I took off the return line to see if fuel was coming back to the tank and cranked while the line was off, it spit fuel out the return and the car fired up, i shut the car off quick and reattached all the lines, waited a bit and then fired her up again, it started right up and actually ran better(smoother) than it used to for a couple minutes but then as it warmed up it started to do the revving idle thing again. Dammit. The idle won't drop below 2,000rpms and bounces 100 or 200 rpms every couple seconds, like a pulsation.

I don't know, i had hope that some of the small repairs i did would have helped, maybe now i should try setting the tps and idle speed again.

anyways, the fuel installation is complete for now, the new lines will go in shortly once the injector clips and new FPR get here. So just for the heck of it, anybody else able to confirm I will be okay running the 4 x 720cc's and ythe 255lph pump with the stock fuel pressure regulator for now??