Fuel Pressure regulator

[NoHachi]

Hi everyone,
Just a few remarks from me, but I'm just going on common sense. I haven't had any experience with a 4A-GE specific fuel system.

1: nmwisima's fuel pressure regulator question:
I really don't think there is something like a electronic fuel pressure controller on the GZE. Think about it: why would toyota bother tinkering with the fuel pressure, when they could more easily adjust the ECU for under boost conditions?\
I think I know what your friend was referring to. A fuel pressure regulator always adjusts fuel pressure such that the pressure at the injector is a constant value over the pressure at the injector outlet (intake runner). That means that the injector always injects the same amount of fuel given a fixed time period. Lots of people think that it raises pressure at WOT, but that is not the case! In NA engines WOT means high intake vacuum and thus low fuel pressure. It lowers the pressure!
FI engines run boost (=positive pressure) at WOT, so the regulator then raises the fuel pressure so that the pressure difference stays the same.

The pressure regulator could be made electronic, but i have yet to see one on a engine. The old scool regulators work plenty good and are still widely used. You could check this easily, just look at the fuel rail and pressure regulator (should be at the end of the rail). Any wires going in there means something fishy is going on.

@filh: Please don't change anything without measuring first!!!!! The std lambda probe is more than good enough for this. They are excellent at detecting the lean condition that could be the source of the problem you describe. I think your AE86 should already have one, so just hook it up to a cheap lambdadisplay. Ignore al of the figures where it says what lambda is at. All the std sensor is is a switch that switches over at lambda = 1. Thats exactly what you want to know.