injector upgrade - Toyota Yaris Forums

CTScott · 01-14-2015, 08:43 PM

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.

01-14-2015, 08:43 PM	#2
CTScott ULTIMATE View User's Garage Drives: 09 5dr LB, 2x 08 3dr LB Join Date: Oct 2008 Location: USA, CT Posts: 13,460	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. __________________