Aram's 3SGE Beams Levin Coupe

[Celica RA45]

aram have you got a return less system like the std altezza. the return is near the fuel pump in the tank and std pressure is 62lbs like std if its hunting check your airflow meter and see also that you havnt any obstruction
also if you have a reg on the fuel rail ajust it up more till the hunting stops
try alll of these things

[Aram]

I have a return system:







What could be wrong with the airflow meter, dirty air?

I also wanted to ask if it is bad that the pressure creeps up to 4.5 bar under throttle?[/img]

[Celica RA45]

your pressure should be 62 lbs on idle and at full wot should be the same pressure
on my race car mine is set to 75lbs and going through the rev range it only drop 1lb in total
if yours is dropping off you might have a fuel pump problem ,also i dont trust the pressure guage that comes with some adjustable fuel regs
also some fuel regs cant handle high fuel pressure

[Celica RA45]

your pressure should be 62 lbs on idle and at full wot should be the same pressure
on my race car mine is set to 75lbs and going through the rev range it only drop 1lb in total
if yours is dropping off you might have a fuel pump problem ,also i dont trust the pressure guage that comes with some adjustable fuel regs
also some fuel regs cant handle high fuel pressure

[Aram]

I have a walbro 255 pump, so it should be capable of keeping up.
But I will check the regulator, maybe it is not suited for this pressure, although it is sold for race cars.
I have a aftermarket pressure meter not sure about the quality.

[Celica RA45]

im using a magnatec fuel pressure reg and a bosch motor sport pump 910 which is 130 litres per hour .dont like walbro at all

[Bean]

I'd hazard a guess that 255 is simply too much for the system to swallow.

[Aram]

Lol, I never would have guessed I could have to much flow in the fuel system.

Is that bosch an internal pump?

[Bean]

you and many others - but at the end of the day it's better to have a matching pump for the application for various reasons - your 255lph pump is good for 400+ hp

and to answer your question the 910 is an inline pump so outside the fueltank. There are many Denso pumps that would fit your setup and wil provide good reliability. 115-130lph should do for your engine

[Celica RA45]

any way before you change any thing use a mechanical guage and rev the motor to 5000 and see what the pressure is doing

another idea 1st .you say its hunting going up and down on idle
ok check with some wd40 and spray around where the manifold bolts up to the head to see if you have some vacuum leaks while the motor is idling if it goes down you have a vacuum leak if nothing happens go to the pressure test