Fuel Pump Issues!

[Blackkers]

43.5 psi with the air hose OFF the fuel reg. That's standard base pressure anyway. What ecu is in the car?

why does this car even have an adjustable fuel reg if the fuel pump was factory?

[cav33r]

Stock ecu with a re map. And i have no clue it was just the way i got it when i bought it. It already had it on.

[cav33r]

Problem solved turned down the fuel pressure and now running like a dream

[Ben C34]

Would pay to get the mixtures checked out. Obviously dropping the fuel pressure reduces fuel flow. Wouldn't want to melt pistons due to running lean.

[Blackkers]

Would pay to get the mixtures checked out. Obviously dropping the fuel pressure reduces fuel flow. Wouldn't want to melt pistons due to running lean.

OP this is a very good idea.

If you're in sydney you could ask Johnny to do it, he might even set your fuel pressure properly for a small fee

[Kane_R32]

Old pump would've worked because it was never flowing the fuel that the new pump was (i.e overly rich/piggish mixtures)

What reg is it? 1:1 rising rate is preferred.

[cav33r]

From what i can tell its a ebay spec one. Currently looking for a better replacement one

[Ben C34]

Get a stock one.

[cav33r]

I have a top mount fuel rail with 750cc injecorts and a plenum waiting to go in Along with a hypergear atr43ss2 turbo z32 afm and a powe fc so i think i may need one when it comes to tuning in the future

[Ben C34]

I have a top mount fuel rail with 750cc injecorts and a plenum waiting to go in Along with a hypergear atr43ss2 turbo z32 afm and a powe fc so i think i may need one when it comes to tuning in the future

Nope. Don't need one.

[Badgaz]

yeah what ben said....adjustable fuel pressure regulators were a thing when upgrading injectors was an expensive proposition, you should only ever need a stock regulator if you run the right pump for the right injectors....most if not all injector flow rates are tested at 43.5psi....your fuel pump just needs to be able to keep up that pressure when the injectors open.

[Blackkers]

i doubt the stock reg will fit in that rail though. forget rising rate too, just set and forget

[Dose Pipe Sutututu]

i doubt the stock reg will fit in that rail though. forget rising rate too, just set and forget

possible, if you use those EFI Hardware adapters..

I was going to do that, but thought what the heck.. fit an external and have control over the rail pressure.

[Blackkers]

What is the point of a rising rate reg? something about squeezing more fuel out in the top end or something?

[Ben C34]

What is the point of a rising rate reg? something about squeezing more fuel out in the top end or something?

That's right. They kind of had a use when ecu's couldn't be tuned.

Now they have no real use. Get correct size injectors and tune away.

[Badgaz]

i thought they were all rising rate and it was only the ratio that changed.

[Ben C34]

i thought they were all rising rate and it was only the ratio that changed.

The rate is the ratio.

[Dose Pipe Sutututu]

That's right. They kind of had a use when ecu's couldn't be tuned.

Now they have no real use. Get correct size injectors and tune away.

eh?

All fuel regulators are rising rate.. as you increase boost pressure, fuel pressure is increased.. it's only NA cars that just run 3bar (or whatever) when there's no vacuum.

[GTSBoy]

The purpose of a normal fuel pressure regulator is to maintain EXACTLY the same pressure drop across the injectors regardless of what the downstream (manifold) pressure is. So, it doesn't matter if the manifold is in vacuum, at atmospheric, or boosted to 2 bar, if the reg is referenced to the manifold pressure then it will make the fuel rail pressure go up and down with it, maintaining the same delta P. This is desirable because the spray pattern generated and the quality of the atomisation is a function of the delta P.

That could be thought of as rising rate, but it's not really, as it is completely linear. A true rising rate reg will add MORE pressure to the fuel as the manifold pressure rises. As has been mentioned before, this was a common cheat to get more flow out of injectors without ruining the idle and low load mixtures when adding more power.....back in the bad old days.

[zebra]

I remember when those Farking shitbox Malpassi 2:1 regs were all the rage.