I'm running full turbo decat exhaust, front mount intercooler and heatwrapped unequal headers and it was running lean so was advised to add bigger injectors which I added yellow 440cc injectors but whilst being mapped is still running lean at higher revs, the fuel pump has also been uprated to a walbro 255, the garage is sorting it out but can anyone advise me on the problem?

 

hi mate
i'm assuming its not a whacking great big turbo you got on it, cause that setup sould be fine with 440s. mine has a VF23, 440s, standandard TMIC and full system from up-pipe back, and they mapped it to 86% injector duty and 1.2bar boost and its its not lean. i would have thought your mapper would have had a good idea what was up?? if its 2nd hand 440s maybe they need flow tested/cleaned? is it still running a MAF? this may be dodgy and giving false airflow readings which can cause the car to run lean too. I'm assuming the boost isn't creeping right up at higher RPM?
hopefully simon or one of the mappers will be along in a minute who'll be able to give some good solid suggestions for you!

all the best
Ash

 

You didn't mention the turbo but assuming it is standard or correct to run with the 440cc in line with boost, the more common reasons for not holding the correct AFR are Maf sensor fault or Maf needing to be rescaled, faulty fuel pump, faulty fuel pressure reg, fuel filter, vacum hose to reg split.

 

Ash what sort of power are you running with your setup? The turbo is the td05, they were 2nd hand injectors but have been flow tested and cleaned, i think they do have an idea said could be the fuel pump wired up wrong as it was my mates and he installed it or something to with the the fuel pressure ? Was hitting 1.4bar on Saturday as it was cold day but usually hits 1.3

 

hiya mate
so with a sports cat exhaust system, manual boost controller, 440s, and vf23 i'm getting 280bhp out of my V3 WRX wagon. the guys said it was mapped for 1.2 bar on the dyno, but i see 1.3bar in the real world so power might be a wee bit more too. like i say, thats with my mapper saying he's not by any means pushing it so could have got more but i'm pretty happy with a solid map with no knock.
Thing is my injectors are only at 86% so there is plenty room left to rich it out further or for it to make more power. my boost falls away after peaking at about 4000rpm, so my aim is an electronic boost controller to hold the boost better at high rpm. as it is it continues making power all the way to the redline, even with fall boost, so should see at or past 300bhp.
i don't know which TD05 you have? 16G, 18G, 20G? for 16 440s would be good, maybe for 18G (??) but whacking big 20G might need 500cc+?? not totaly sure. but even with the 16G i would think you would be comfortably above 300bhp with your decat and FMIC.

don't know how much of that is any use to you so i thought i'd just stick down my life story lol
but you have probably answered your own question with a possibly dodgy fuel pump or some kind of fuel pressure problem.
hope you get it sorted

best of luck Ash

 

oh i have walbro 255 aswell, so quite similar setups and i'm assuming your turbo will be similar size to mine
Ash