I installed a Greddy kit recently with the Emanage ultimate and I have had lots of problems with the idle. When the car warms up the idle is ruff and the car dies on occasion if you blip the throttle. The cold idle is great, I checked the fuel trims and they are right at 2% and the wide band is reading 14.7-15 A/F. So I wacked the map, cleaned the throttle body and cleaned the IAC none of which worked. So I am at a loss as to why the car won

 

Does anybody think the turbo could be causing to much of a vaccum to form and starving the engine? It seems that I have to rev it alittle higher also now that the turbo is on from a stop.

 

turbo causes no vaccum, engine / pistons cause vaccum with tb closed.

 

Mine idles a little bit rougher when warm than stock, but it never dies. It is just something I have goatten used to. I hardly even notice it anymore.

 

It can cause a larger vacuum when blipped over stock, since the turbine has mass it can not instantly respond to the throttled demand. So with a turbo, piping and intercooler there is a large restriction to air flow which allows the engine to starve for air momentarily, then when you let off there is increased pressure which overcharges the intake momentarily.

They being said, I have adjusted the BOV so that is on its softest setting. I am not 100% but the synchronic BOV may fix this. If it opens under deep vacuum and allows a small amount of air to enter.

The only other thing I can think of is that Greddy did not correctly choose the factory and or aftermarket injector Size and I/J lag time. However the LTFT's at idle and AFR look good. The currently have the following:

Before After
I/J Size 360 560 cc/min
I/J Lag Time 0.1 0.34 msec

Other than that I am lost.

 

I was having this problem and a whole bunch more.. It ended up being my MAP sensor which had gone bad. A new one and a reset of the ECU and its much better and never stalls.
When the motor is cold though I do still get that low idle and almost stall feel though, but that's only when first driving.