turbo problem i never faced
 

hi guys.
i turboed around 15 car in my life but i'm facing a problem i never faced before.
some of you know i'm turboing my winter beater aka the hyundai accent 1999.

here the car and setup.
hyundai accent 1999 1.5l sohc 12v , 302 000km
run like brand new before the turbo

CXRacing T28 turbo w/ 14 psi internal wastegate ( machined to 10 psi )
CXRacing blow off valve
CXRacing silicon couplers & clamps
CXRacing intercooler
OBX 8:1 fmu
GlowShift boost gauge
GlowShift oil pressure gauge
GlowShift wideband gauge

there no leak at all , i checked like 10 time.
i don't think it's related to the fmu because
1* plugged or not = same problem
2* 8:1 seem to be the perfect one for my goal and my stock injector.
3* tried with friends 6:1 and 12:1 = same thing
it may be the timing... but those engine have automatic timing wich is supposed to be good for 12 psi ( 7 professional told me )
the spark plugs are 1 step colder
spark wire are new from 2 month and are ok
ignition coil are ok too
i replaced fuel filter

the rpm just stay there ( over 4k ) , wideband hit its maximum value ( 20 ) , making no power at all , engine backfire , and oil splash out of the oil cap on valve cover when i release gas , so can't even get over 4 psi now.

with my experiance , if my ring was the problem , it would give problem without boosting... and without , it run like a brand new 2012.

at idle it is perfect. the only small trouble is when i rev it and stop , the rpm go under 300 rpm for half a second and come back to normal.

never faced this before and i don't know what is wrong there

Is it blowing oil out the dipstick or blowing the oil cap off? Either way if it is making that much blow-by there a serious compression leak somewhere. Maybe there was some metal shavings somewhere in the turbo setup that the engine ingested and trashed the rings. I would start with a dry/wet compression test first.

ok i will try to find a cpmpression tester tomorrow.
but if it was my ring , shouldnt my spark plugs be black ?
they are really clean and also looking the piston thru the spark hole nothing indicake a ring problem.

i'm wrong ?

Does the AFR go lean all of a sudden, or does it gradually drop off?

tough to say over the internet. post some pics. im suprised you turbod an engine with 190k miles on it...... the backfire is a lean condition, the lack of rpm increase is due to the lean condition. the engine doesnt have enough fuel(power) to increase revolutions over 4k rpm. if you hit 20:1 afr for long periods of time its almost a guarantee you damaged your pistons. the oil coming out of the oil cap is blowby which is going to be more prevelant on an engine with 190k miles.

if your hitting 20:1 afr then your fmu is not working or you have it hooked up incorrectly. an fmu is not a tune and should never be used when running more than 6 psi boost. fuel system component damage can occur when raising line pressure too high.


did you do the compression test?

fmu are MADE for up to 10 , not 6.
anyway the fmu is working great.
i got a fuel pressure gauge and its around 40-45 normal cruise and up to 80-110 ( dont remember exactly ) when the boost come. so fmu is working as it should.
the wideband go to 20:1 suddently ( when the rpm get stuck )
if i can get the engine to hit cutoff ( not WOT for low boost ) the wideband show around 14-15.5.

about compression test , i dont feel the need of it.
if i had lower compression it wouldnt feel like 92 hp but much like 80 or so.
i will do a test later for sure tho.


i found my problem.
my injector seem to be the original one from hyundai in 1999. they are going away.
when i found it was my injectors i called the shop i was working for and boss said its definitivly the injectors.
i will find 4 tiburon/elantra/sonata 1.8 or 2.0L injectors to fix the problem.
may take a long time as here junkyars only take 2008+ and i need 97-2006 injectors.

i wonder if 2.4L santafe injectors will be too big ? way easier to find.

Does that engine have a mass airflow sensor? if so that it your reason for hitting fuel cut off. You most likely maxed out your maf parameters causing fuel cutoff.
This is where things start to get expensive.
you will need larger injectors, larger maf sensor and a custom tune. If u get to this point then your fmu is no longer needed.
My suggestion is to continue to use the fmu and lower the boost level until the fuel cutoff stops happening. Had this problem with my 92 eagle talon turbo.

yes it has MAF sensor. first it was between the turbo and the air filter
and then now where it whould be as pro told me , on the piping between the intercooler and the blow off valve.
here in canada there alot og accent boosted and i dont know anyone that needed to get a better maf sensor. why would I need to ? can you explain ?
mine broke and i found a used working one ( took 27 days to find one ) for 35$. if i really need to i will replace it again for a better one but i don't plan to change it if its not REALLY needed.


also the wastegate is a 14 psi internal one. i opened it cut the spring and tested it until i get 10 psi , and welded it. i wont do it again because i had too much trouble welding it.

you think 2.4 or 2.7 hyundai injectors will be too much ??
because i can't find tiburon/elantra used injectors. too old for our junkyard.
but i already found 8 set of 6 injectors from 2.7 santafe and 2 set from a 2.4l santafe/sonata.

If you are trying to use upsized injectors, what will you be tuning it with?

Get the junkyard injectors flow tested.

the FMU.
i wont use electronic on a car i get rid after this winter.