accent x3 turbo problem

[NvidiaForTheWin]

hi all

im having a problem with my turboed accent.

i know what those engine can handle don't worry about it lol

my car & setup
accent 1999
1.5L sohc stock
302 500 km ( yes , original but anyway... )
CXRacing t28 10 psi
CXRacing bov
CXRacing intercooler
GlowShift wideband
GlowShift boost gauge
GlowShift oil pressure
custom made vaccum manifold
OBX fmu 8:1
tiburon 2.0L injector
NGK sparkplug ( dont remember model but 1 step colder , gapped to .30 )
all the rest is stock

i checked about 20 time , no boost/vac leak at all.

the problem is when the boost come around 4-5 psi ( it always depend ) the AFR go really lean ( show 20:1 ). the engine rpm stop going up.
if i hold it , SOMETIME the afr show 20 then 16 then back to 20 ( a 5 second WOT run )

for info , my fuel pressure hit 70+ so the fmu is doing its job ( without fmu = 45 )
also my stock fuel pump is in really good shap and hold up the pressure.

i tried unplugging the following but nothing change
#1 sensor
#2 sensor
fpr
fmu
maf

even 4 tuning shop have no idea what is wrong.

i dont think its fuel cut because fuel cut is agressive and its not the case.

im lost... anyone have an idea ??? thanks

EDIT :
seem to be MAF related ( bein maxed out so the ecu cut fuel ).
what you think ?
if you think tis the problem , how i fix it ?
i know i could get a bigger maf but i stay with hyundai parts and used hyundai part are hard to find here.
maf clamp sound to be a better solution if its the problem... is it hard to make ?

[krazymikeyGT]

try emailing some of the turbo users.

there are a few who can help you

[NvidiaForTheWin]

Originally Posted by krazymikeyGT

try emailing some of the turbo users.

there are a few who can help you

thanks for your reply.
unfortunately finding member with FMU setup would take long time IF there is at least one.

i could go with AEM F/IC but in 2-3 months so i need to find a fix so i dont blow it this winter....

PS even running 5 psi i have the same problem so lowering from 10 to 5 psi will not fix the problem.

[steelcoffinx3]

You could be getting spark blowout which would make your wideband read lean, I ended up gapping the plugs down to around .020 running 9 psi with a t25. Also disconnect the first o2 sensor and then reset the computer and run it like that or the AFR will be inconsistent under boost and do weird things. Your going to want the tiburon/elantra maf sensor so you don't run rich off boost. I'm surprised the stock fuel pump is holding up, my 12:1 fmu made almost no difference without a walbro inline. Check out my thread 99 accent turbo

[NvidiaForTheWin]

thanks i will try that.

for the 2.0l maf... mine run rich only when cold and the engine run bad.
when it warmed up a bit then the afr is around 14.5-15 wich is the same as my brother 03 accent GS when it was stock.

[synntax_error]

I agree with your thinking the maf is maxing out and cannot read any higher, but spark blow out might also be a problem.

I don't think the 2.0 will be enough but may be wrong. I would try something larger, maybe a GM out of 93-97 V8 Car, like the impala,firebird or camaro.

[NvidiaForTheWin]

thank you.
i dont think its spark blowout because i gapped my plugs to .25 and no change.
before i start trying the boost my spark was super clean ( 100-200 km ).
since i started to try the boost ( under 5 km done ) my spark are all black.

anyway... i can find the maf you suggest but for 120$ the cheapest i found.
but i go with aem FIC next month ( i decided to even if i get rid of the car end of spring anyway ill put it in the elantra and i can tune it meself )
.
120$ for a month......... lol ?... NO.
this is why i need a temp CHEAP fix . i know the engine can blow running poor.

[regit]

Sounds like a fuel issue,leaning out under wot, .with over 300000kms, I'd do a compression test first.

[NvidiaForTheWin]

i tought i answered.... but i forgot.

the problem is fixed.
i did a maf clamp ( 4.3v zener diode ) for 2$.
i can now hit 10 psi , afr is 11:1 - 11.5:1 ( hit 13:1 half a second only when engine is not at operating temp ) , and no problem at all.

still , thanks you all for the help