Poor idling after high rev ( 4G63 )

[spuzzle]

All zth members, need some help to sought out my engine idling problem.

my engine idling after high rev is not stable where it drops to 300 or 400 rpm and sometimes do shutdown the engine. it is so difficult to drive in urban where u need to change gears always. my foreman did few troubleshoot such as changing ecu, airflow sensor, stepper motor, service throttle body and few more things but still the same. it happens with ac on or off.

engine spec:
-vr4 block
-evo head
-evo wiring
-evo ecu
-560cc injectors
-18g turbo
-tomei cam 270
-1.5mm metal gasket
-hks ssqv
-boosting 1.3 -1.5bar

thanks in advance for your opinions and suggestions

 

[bertdeen30]

too rich for the fuel ?? have fuel regulator to tune ? cause my car same same like yours ..but i put my fuel regulator lower abit and run smoother.

after i mod with my 560cc and wal bro ..and it become too rich and cannot go to high rev..
too much petrol RICH !!

im now tuning with SAFC NEO i hope it work lo...but so far ..

if Intercooler piping and vacum hose all is plug and fit ..ignition coil / spark plug / plug cable is ok.
then should have no more problem..anything we talk in msn la..hehehehe

 

[spuzzle]

too rich for the fuel ?? have fuel regulator to tune ? cause my car same same like yours ..but i put my fuel regulator lower abit and run smoother.

after i mod with my 560cc and wal bro ..and it become too rich and cannot go to high rev..
too much petrol RICH !!

im now tuning with SAFC NEO i hope it work lo...but so far ..

if Intercooler piping and vacum hose all is plug and fit ..ignition coil / spark plug / plug cable is ok.
then should have no more problem..anything we talk in msn la..hehehehe

fuel regulator tune to 45psi....maybe because of boost leak or BOV....have to go through it after back fr AU.....long time din see u online?

 

[bertdeen30]

i always online leh ...~~~!!!! MSN same my nick name leh ..@ hotmail.com

45psi ? 560 CC in Original evo1/2/3 engine base??

i use 45 psi too rich

im using Vr4 /sard 37 psi / fuel pump walbro 255 / too rich .. im using SAFC neo tune down 10 % of petrol and slowly up.

when low rev it still can drive within 1k-3k or 3.5k rev .
more than that the power like lost away. and blablablabla sound from atzos .

after tune by safc neo no more such stupid sound

 

[AZRacing]

hello there...just to share my opinion...
i think this problem is because of the BOV...that is according to my mech...
coz the BOV valve is not closing fast enuff...i am having this same problem with my GSR...
and so is my frenz GSR also...

with a/c on...it happens more often...with out a/c it rarely does...is this the same as yours?

 

[spuzzle]

i always online leh ...~~~!!!! MSN same my nick name leh ..@ hotmail.com

45psi ? 560 CC in Original evo1/2/3 engine base??

i use 45 psi too rich

im using Vr4 /sard 37 psi / fuel pump walbro 255 / too rich .. im using SAFC neo tune down 10 % of petrol and slowly up.

when low rev it still can drive within 1k-3k or 3.5k rev .
more than that the power like lost away. and blablablabla sound from atzos .

after tune by safc neo no more such stupid sound

used to see u online when u in HK but now seldom....my setup almost same as yours....walbro 255lph fuel pump and sard regulator....my engine running rich on high rpm around 6-7k....plan to get standalone soon....budget too tight because need to paint the car first

Bump:

hello there...just to share my opinion...
i think this problem is because of the BOV...that is according to my mech...
coz the BOV valve is not closing fast enuff...i am having this same problem with my GSR...
and so is my frenz GSR also...

with a/c on...it happens more often...with out a/c it rarely does...is this the same as yours?

oooo......my problem exactly same as yours.....with a/c on more often and without a/c rarely does.....need to change with other BOV and try if it's really the BOV......thanks AZ for your opinion

 

[saolabi]

After I installed a voltage stabilizer and a ground kit, idling is no longer a problem..

 

[AZRacing]

I've installed the VS n Grounding quite a while ago...but it is still the same...=(

 

[ftzone]

it is most likely the blow off valve.
it is common with mitsubishi engines that uses atmo vented bov. heck... in fact it's a common problem for most turbo charged gasoline engines.

The cause:
Missing air released by the blow off valve which did not enter back into the intake system causes the ECU to miscalculate the airfuel ratio. Making the engine temporary super rich at the time of the throttle release.

recommended solutions
1. Adjust the BOV to harder setting (if adjustable type like GReddy Type S/RS).
2. If you have fuel management (piggy back) like SAFC NEO, GReddy E-Manage, there is a function to counter this problem.
3. HKS EIDS Type K for Mitsubishi * Electronic Air Flow Correction for the above problem.
4. Use Recirculating BOV.

Hope that helps.

 

[spuzzle]

thanks all bro's for your suggestions and opinions.
finally the problem solved after fine tune the air fuel ratio. too rich of fuel which cause the poor idling.