injector upgrade

[Ryze268]

Not sure if you guys know but I have embarked on boosting my 2NZ-FE, I have in 1ZZ injectors however while tuning with the AFC Neo, we're running into lean spots while under boost.

My tuner said that I should upgrade my fuel system but that's kinda expensive (I plan to do it, just can't right now). He then said bigger injectors and a bigger fuel pump should help. While looking up new injectors I found these:

http://www.ebay.com/itm/11-12-SCION-TC-FUEL-INJECTOR-2-7L-4CYL-23250-36010-110916-/350853169253?pt=Motors_Car_Truck_Parts_Accessories&hash=item51b07a8065&vxp=mtr

They looked weird compared to regular injectors and I was reading up on them, turns out they're AR engine injectors.

The Tumble control valves, along with new 12-hole high atomizing long-nozzle fuel injectors, reduce the amount of fuel adhering to the intake ports and therefore maximize fuel economy and reduce harmful emissions.

Do you think these are worth having?

[CTScott]

The 1ZZ injectors should be fine up to at least 8psi of boost. You more likely are having issues due to flow into the injectors (from the stock pump) or fuel pressure (ideally fuel pressure should increase by 1 psi for each 1 psi of boost). I have modified stock fuel pressure regulators for people to give them a cheap upgrade by increasing the pressure regulator from the stock rating (41-45 psi) to that plus their max boost (i.e. 43 to 51 for an 8 psi setup). By doing that you account for the maximum plenum pressure, but then have to pull a little fuel at lower boost to compensate for the extra pressure.

[Ryze268]

The 1ZZ injectors should be fine up to at least 8psi of boost. You more likely are having issues due to flow into the injectors (from the stock pump) or fuel pressure (ideally fuel pressure should increase by 1 psi for each 1 psi of boost). I have modified stock fuel pressure regulators for people to give them a cheap upgrade by increasing the pressure regulator from the stock rating (41-45 psi) to that plus their max boost (i.e. 43 to 51 for an 8 psi setup). By doing that you account for the maximum plenum pressure, but then have to pull a little fuel at lower boost to compensate for the extra pressure.

sweet, could you do the same for me. I don't mind paying you if this would solve my problems.

[CTScott]

sweet, could you do the same for me. I don't mind paying you if this would solve my problems.

It would very likely help. Fnkngrv had me modify one for him and it worked up to about 12psi of boost, where at that point the stock pump couldn't flow enough fuel.

How many PSI of boost are you running?

I usually have people ship me their regulators to adjust, as new ones are crazy expensive (about $80+). In your case, that would probably be cost prohibitive for the shipping time and cost.

[Ryze268]

I'll be running a maximum of 8psi

Is this the correct one:

http://www.ebay.com/itm/Fuel-Pressure-Regulator-for-Toyota-Lexus-Scion-honda-FP10280-11B-123280-22010-/151443075171?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3AToyota&hash=item2342b5f063&vxp=mtr

[CTScott]

I'll be running a maximum of 8psi

Is this the correct one:

http://www.ebay.com/itm/Fuel-Pressure-Regulator-for-Toyota-Lexus-Scion-honda-FP10280-11B-123280-22010-/151443075171?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3AToyota&hash=item2342b5f063&vxp=mtr

That is an aftermarket one that is supposed to be compatible. The cheap aftermarket ones look very thing. I am not sure if they would hold up to the modification process (which consists of increasing the spring pressure). I have to adjust, test and repeat a bunch of times until I get it to the correct setting. It is tricky, as there is no going back if an adjustment takes it too far.

[Ryze268]

That is an aftermarket one that is supposed to be compatible. The cheap aftermarket ones look very thing. I am not sure if they would hold up to the modification process (which consists of increasing the spring pressure). I have to adjust, test and repeat a bunch of times until I get it to the correct setting. It is tricky, as there is no going back if an adjustment takes it too far.

Sounds like a tedious process, I don't know what we'd do without you Scott :bow:

[CrankyOldMan]

How do you verify the new pressure?

[CTScott]

How do you verify the new pressure?

I have a test fixture that I built that uses a stock Yaris fuel pump to test the original and modified regulators.

[CrankyOldMan]

I have a test fixture that I built that uses a stock Yaris fuel pump to test the original and modified regulators.

How did I not see that coming? This guy is like a Niels Bohr with a Yaris or something!

[fnkngrv]

I know that you are looking for a relatively quick answer, but I might still have my OEM regulator kicking around, or maybe I shipped it to Scott? Anyway, Cranky he actually had me ship my AEM 320lph to test it on his bench before I sent it back to AEM to confirm whether or not I was experiencing a faulty pump. AEM was pretty impressed when I talked to them about it.

[Ryze268]

I know that you are looking for a relatively quick answer, but I might still have my OEM regulator kicking around, or maybe I shipped it to Scott? Anyway, Cranky he actually had me ship my AEM 320lph to test it on his bench before I sent it back to AEM to confirm whether or not I was experiencing a faulty pump. AEM was pretty impressed when I talked to them about it.

Would be great if you still have it. Scott and I are working on something, just waiting for him to let me know if he's successful.