fuel pressure and 4age

**Scorpion** · 25-02-2006, 10:26 AM

From my simple perspective you can put as high a flow-rate pump in as you like but as long as the regulator can handle the pressure from the pump all you'll achieve is to increase the volume of excess fuel past the regulator and back to the tank, with the restriction of the return fuel pipe being the limiting factor. If the regulator is doing it's job it'll just feed fuel through to the injectors at whatever it's design pressure is.

**oldcorollas** · 25-02-2006, 02:28 PM

exactly, since at idle you use least fuel.

to test, get pump, pressure gauge, and reg (and some fuel

).
hook it up, run the pump and see i pressure goes above the regulated level. if so, reg is too small.
thats about it.
stock toyota ones can flow at least 150L/min (small Walbro), and likely 220L/min at least (big Walbro)

**45aken** · 27-02-2006, 11:58 AM

the pump i got is a 255l/m walbro. im not here to fight about why i got it and whats the point-i have it now and might as well use it

+the jun factor

**Scorpion** · 27-02-2006, 01:14 PM

Try this url for Bill Sherwood info on fuel pressure.
http://www.billzilla.org/4agstock3.htm

Details under "4AGE EFI system" heading.
Cheers.

**TopSecret** · 14-04-2006, 08:40 PM

One last question for this topic. I'm running an AE82 lift pump to a surge tank and a VL pump feeding the motor in an AE86 like many others are doing. Now fuel economy is b/s for a 4 cylinder, 450KM to a 50L tank.

What is the problem in this situation? Why isn't the fuel press. reg. setting the pressure at what is needed for the engine? What's the issue here?

**30psi 4agte** · 15-04-2006, 01:49 AM

how does the car run?

does it run rich? if not its unlikley that its the reg causing your prob.

Whats the fuel pressure at? if you dont know you should find out!!!!

**TopSecret** · 15-04-2006, 08:19 AM

The car runs well, just really rich. Heaps of carbon sitting around the tip of the exhaust, only 450KM to 50L.

I dont know what pressure my motor is running at, but the standard fuel pressure is around 35psi at the reg and the pump runs at 75psi. But the pump feeding the motor, in my case the VL pump, runs at around 100psi. I just dont see why its running so rich, i've always thought it was the reg, but when i purchased another second hand one nothing changed. Maybe that one was buggered too?

**30psi 4agte** · 15-04-2006, 06:47 PM

i think it may be more to do with the extra amount of fuel flow that the bigger pump is pumping causing the car to run rich. unless there is another prob somewhere!