My 05 EVO 8 when idling at a stop dies and basically acts like it's ran out of gas....runs great on the hwy. But also occasionally while driving acts like it's not taking fuel.

Plugs have less then 3k miles, tuned on 93...oil was changed this past weekend. I can hear the fuel pump humming like normal.
AFR hovers around 14.7-15.0 at idle...at full boost i'm at 11.5-10.9AFR - so the tune is safe.

Mods:
SD - GM IAT, Grimspeed 3 Port Boost Solnoid & 4Bar Omni Map Sensor.
4G64 2.4 Stroker with Manley Rods & Pistons
GSC S3 Cams w/Vishnu Cam Gears & Valvetrain
ETS IC w/Tial BOV
FIC 1250 Inj & [1] 255 f/pump
Moroso Catch can w/-10an lines
Stock evo 9 manifold & turbo.
Stock Ems with HOP tune. Built also by HOP.

Thoughts?

 

No expert by any means, but could it be the idle air control valve?

 

Could it be dirty or needs to be adjusted?

 

Possibly could be on its last legs. Do you know if the BISS is set properly too?

 

Please enlighten me on BISS?

 

This is just a copy and paste of mine from another thread:

Have you checked if your BISS (base idle set screw) is set properly and that the car had time to relearn idle? I see this question pop up frequently, and almost every time it is the issue. If you have a tactrix cable and Evoscan you can check your base idle really easily. If you have it, go into the program and go down to the actuator box in the bottom right. I think it's the last option in that box, it will say biss adjuster or something along those lines. Activate it. If you car stalls, loosen your biss WHILE the actuator is still on. If the idle is too high, tighten the biss. After the idle is where you want it let the car idle ten minutes with all accessories off (climate control, lights, etc.). Then let it idle for ten minutes with everything on. Should have
your idle 100% good after that.

 

I do not have evo scan...i'm a newbie when it comes to the evo platform.

 

It's something worth investing in for the future. Do the idle relearn steps at least, will still help. Let the car sit for ten minutes idling with most things off. Then do another ten with lights/ac/radio/rear window heater on etc.

 

Can I do the idle relearn w/o the evoscan?

 

Yep. It wont ever be perfect without properly adjusting the BISS (base idle set screw) but it wont die on you in traffic or anything. Will probably just idle a little higher.

Do NOT **** with the BISS screw without Evoscan or some other electronic method to set it. I help so many local owners reset their idle because someone in thw cars life time has tightened it and the car will want to die, and they don't know about relearning idle.

 

How do I do the relearn?

If I wanted to buy the evoscan, where can I source/price it?

 

Basically just go idle your car for a bit. If it sputters and dies out just restart it and add on an extra minute. Process takes me about 25 minutes, my BISS is stripped and unadjustable due to a previous owner so I have to go through the relearning process everytime I unhook my battery.

Evoscan can be purchased at www.evoscan.com. The website will have the answers to your questions as well as tell you any hardware you need.

 

Always start with a BISS
adjustment.

 

Listen to what is said about BISS. Don't mess with it without evoscan as it's needed to park the stepper motor.
adjust the BISS without doing that will lead to idle fluctuations guaranteed.

I'd do it for you if you were in Ireland

 

Truth. If it's not adjusted right, the IACV has to compensate like crazy to get things back to normal and the car will forever have problems. It must be set correctly before anything else can be done.