Had Frst OFAB EFI on my S2 rst for some time now and its always been pretty much on the button with a standard frst engine,standard injectors, ecu etc.
It also had a steady AFR of high 14s at idle and dropped to 11/12 on boost.
decided to upgrade so i've installed beiges and a collins powerchip ready for when i have the money for a decent front mount.
My problem is now i've installed the chip and injectors now my fueling is all over the place- I can get the AFR flicking between 14.3/1 and 15/1 on idle using the 'co pot' but the on boost enrichment is non existant!
It drops to 13 and steadily raises to 14 )
I'm running a -31 and its not being bled at all so its only at 7psi aswell
any ideas? as i'm trying to home tune to some extent to save some money.
I'm monitoring it with a Vems AFR guage.

 

like you said co2 pot will only sort fuel on idle. its your fuel pressure regulator you want to adjust. standard is 2.5 bar and apparently with beige's it needs to be upped to about 3.0 bar.

 

ah i did wonder about this as i knew higher fuel pressure may help richen the fuel mixture- i'll get me a guage and try that before shelling out for a new chip- guessing its not gonna help as much as i'd need it too though.

 

obviously il say the safe thing and suggest getting it properly set up by a tuners..but, yeh there really isnt much to setting up beiges and a chip if you got a wide band and a fuel pressure gauge, should be fine mate

 

that was my initial thinking but looking at the control this chip has of the fuelling i'm not so sure- seem very slow to re adjust back to idle fueling after a good blat to check it aswell
really not impressed will see how much the pressure changes things
still pulls nice but i wouldn't want to drive it much like it thats for sure!
thanks for the advice mate i'll have a look at the fuel pressure and if it doesn't do the job good enough i'll get me a proper chip

 

wow tryed playing to see if it improved matters with the standard FRST fuel rail and result is i have a nice steady AFR of 12/1 @ full throttle
only at 7psi but its a vast improvement- just adjusted the grub screw clockwise and the idle mixture started richening so i was able to back off the co pot adjustment to maintain a more stable 14.7/1.
kept going till it seemed pretty stable then went for a blast/test and wow wot a difference, tis now a fair bit quicker than my 2litre focus with just 7psi
plenty more tweaking to do but i'm well impressed so Thanks ram
my next question is will i run into issues raising the fuel pressure? I will get a gauge asap to check wot it is currently just wondering?

 

Obviously if you run the pressures too high the pump may not be able to cope or you may damage the internal seals of the injectors. I wouldn't go any higher than 3.5bar at any given point UNTIL its been checked over by a tuner

 

nice one Haz i'll get a guage on there as soon as i can- i didn't turn it too much but i deffo need it checked before i use the car too much
deffo seems to have stabilised the idle and recovery off of throttle etc so hopefully the new injectors are working well now!