I've searched through the limited amount of threads there are regarding adjusting the BISS screw, and also gone through the factory manual. But, I've come up with limited information and help. My situation is like this:

Recently, I had a problem with my idle which turned out to be a malfuntioning IACV. During the process of troubleshooting the problem, I stupidly adjusted the BISS screw and did not keep track of how many turns I turned it. Well, I finally figured out that the IACV was the problem and replaced it.

Along the way, I found out that i needed Evoscan and the Tactrix cable to reset the correct idle in SAS mode. I have the Tactrix cable and downloaded Evoscan to my laptop now. Now, my car is running aftermarket cams. I hooked up my laptop and used ECUFlash and saw that the tuner had set the target idle for my car to 1008 RPM. My question is: when I adjust the BISS screw and set the idle while in SAS mode, do I adjust it to 1008 RPM or the factory idle of 750 RPM? Sorry about the long essay. TIA.

 

750. Once SAS mode is deactivated after adjustment, it should idle @ 1000, in your case.

 

awesome!!! Thanks for the help.

 

alright, update on my dilenma. after warming the car up to operating temps, I turn on SAS mode with Evoscan. But, the lowest i can get the car to idle at with SAS mode on is 900ish to 1000 RPM (that's with the BISS screw fully screwed in). If I turn it out, the idle will rise, but I tried for 15 to 20 mins and still the same. The idle won't go any lower than that for some reason. I remember that I actually turned the BISS screw quite a few times when i first messed with it. I also made sure the stereo, all the fans, lights and any other major power drawing source was off of disconnected. I recently replaced my TB shaft seals with the WORKS ones. Could it possibly be that my BISS screw o-rings are shot?

 

I forgot to add that the car does not die out with the BISS fully screwed in. And, when i had replaced my TB seals, i decided to clean out my TB also and accidentally cleaned off the gray "goop" that goes around the butterfly valve. would this be the source of my problem also? I've read about people painting a layer of "white out" around the butterfly to fix this. Any ideas regarding this? Sorry about the million questions...

 

Haha, I just did the same thing. It looked dirty so i cleaned it off. Now my idle bounces when I'm rolling and disengage the clutch. When I'm stopped it idles at about 1500. My fix was a good deal on another throttle body. Im not sure white out would close up the gap enough. The best way to fix it would be to find out what that gunk is and replace it.

But that is probably Mitsubishi's top secret "I screwed up the throttle body tolerances" band-aid.

 

Oh man... I know what you're talking about.. I tried to clean mine but I had some crap carb cleaner and it didn't clean it that well, so I gave up. Good thing. however I did remove some of it.

I too would like to know what that goop is called and where to purchase.

 

no one knows what that paint like coating on the throttle plate is??? i really don't want to dish out the extra money for a new TB, but i need to get my car running good before AMS gets down here for tuning in June... I looked at my TB again today to check the clearance between the throttle plate and the TB housing and I was able to slip a sheet of paper in between them easily.

 

Hey, I had a problem with the idle from the Idle Speed Controller so I had to replace it.

Even with the new one, I'm having an issue. Is it correct that I need to adjust the ECU with Evoscan? I also have aftermarket cams.

 

i just did this and i don't think my iac is bad, because it was fine before i cleaned the "goop" out. i am hesitant to pull the trigger on a boomba, because i daily drive my evo, and need the reliability. is there any procedure to resetting the idle? i was gonna disconnect the battery, reset the ecu, and start car and idle for 10 minutes with the a/c on. any suggestions would be great cause it'll save me $800 bucks. $430 for the boomba and $300 for the iac!

 

Dow 321

 

Will this work on a stock lancer? I have a different cam and didn't notice idle issues until I installed semi-solid motormounts from RRM. I'm idling about 500-550RPM. Looking to get closer to 650-700. Didn't want to mess with the Base Idle Set Screw (BISS) as everyone tells you not to...

 

Also be aware of this issue...

We now replace BISS screws on all MIL.SPEC throttle bodies with new OEM units because of that you see below:

NEW BISS is in the middle.

 

anyone have the part # on the BISS screw?

 

Is this an adjustment that can be made through ecuflash, or does it have to be evoscan? Will evoscan even work on a stock lancer (2003)?